Blok21

FLY ASH

blok21 — Tue, 20 Jan 2009 06:50:16 +0000

Fly ash is the finely divided mineral residue resulting from the combustion of ground or powdered coal in electric generating plant (ASTM C 618). Fly ash consists of inorganic matter present in the coal that has been fused during coal combustion. This material is solidified while suspended in the exhaust gases and is collected from the exhaust gases by electrostatic precipitators. Since the particles solidify while suspended in the exhaust gases, fly ash particles are generally spherical in shape (Ferguson et. al., 1999). Fly ash particles those are collected in electrostatic precipitators are usually silt size (0.074 – 0.005 mm).

Fly Ash Classification

Fly ash is a pozzolanic material and has been classified into two classes, F and C, based on the chemical composition of the fly ash. According to ASTM C 618, the chemical requirements to classify any fly ash are shown in Table 3.1.

Table 3.1. Chemical Requirements for Fly Ash Classification

	Properties		Fly Ash Class
			Class F		Class C
Silicon dioxide (SiO₂) plus aluminum oxide (Al₂O₃) plus iron oxide (Fe₂O₃), min, %		70.0		50.0
Sulfur trioxide (SO₃), max, %		5.0		5.0
	Moisture Content, max, %		3.0		3.0
	Loss on ignition, max, %		6.0*		6.0
	* The use of class F fly ash containing up to 12% loss of ignition may be approved by the user if acceptable performance results are available

Class F fly ash is produced from burning anthracite and bituminous coals. This fly ash has siliceous or siliceous and aluminous material, which itself possesses little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperature to form cementitious compounds (Chu et. al., 1993). Class C fly ash is produced normally from lignite and sub-bituminous coals and usually contains significant amount of Calcium Hydroxide (CaO) or lime (Cockrell et. al., 1970). This class of fly ash, in addition to having pozzolanic properties, also has some cementitious properties (ASTM C 618-99).

Color is one of the important physical properties of fly ash in terms of estimating the lime content qualitatively. It is suggested that lighter color indicate the presence of high calcium oxide and darker colors suggest high organic content (Cockrell et. al., 1970).

Fly Ash Chemistry

Chemical constituents of fly ash mainly depend on the chemical composition of the coal. However, fly ash that are produced from the same source and which have very similar chemical composition, can have significantly different ash mineralogies depending on the coal combustion technology used. Because of this, the ash hydration properties as well as the leaching characteristic can vary significantly between generating facilities.

The amount of crystalline material versus glassy phase material depends largely on the combustion and glassification process used at a particular power plant. When the maximum temperature of the combustion process is above approximately 1200⁰ C and the cooling time is short, the ash produced is mostly glassy phase material (McCarthy et. al., 1987). Where boiler design or operation allows a more gradual cooling of the ash particles, crystalline phase calcium compounds are formed.

The relative proportion of the spherical glassy phase and crystalline materials, the size distribution of the ash, the chemical nature of glass phase, the type of crystalline material, and the nature and the percentage of unburned carbon are the factors that can affect the hydration and leaching properties of fly ash (Roy et. al., 1985). The primary factors that influence the mineralogy of a coal fly ash are (Baker, 1987):

1. Chemical composition of the coal

2. Coal combustion process including coal pulvarization, combustion, flue gas clean up, and fly ash collection operations

3. Additives used, including oil additives for flame stabilization and corrosion control additives.

The minerals present in the coal dictates the elemental composition of the fly ash. But the mineralogy and crystallinity of the ash is dictated by the boiler design and operation.

Hydration of Fly Ash

Formation of cementitious material by the reaction of free lime (CaO) with the pozzolans (AlO₃, SiO₂, Fe₂O₃) in the presence of water is known as hydration. The hydrated calcium silicate gel or calcium aluminate gel (cementitious material) can bind inert material together. For class C fly ash, the calcium oxide (lime) of the fly ash can react with the siliceous and aluminous materials (pozzolans) of the fly ash itself. Since the lime content of class F fly ash is relatively low, addition of lime is necessary for hydration reaction with the pozzolans of the fly ash. For lime stabilization of soils, pozzolanic reactions depend on the siliceous and aluminous materials provided by the soil. The pozzolanic reactions are as follows:

Ca(OH)₂ => Ca++ + 2[OH]-

Ca++ + 2[OH]- + SiO₂ => CSH

(silica) (gel)

Ca++ + 2[OH]- + Al₂O₃ => CAH

(alumina) (gel)

Hydration of tricalcium aluminate in the ash provides one of the primary cementitious products in many ashes. The rapid rate at which hydration of the tricalcium aluminate occurs results in the rapid set of these materials, and is the reason why delays in compaction result in lower strengths of the stabilized materials.

The hydration chemistry of fly ash is very complex in nature. So the stabilization application must be based on the physical properties of the ash treated stabilized soil and cannot be predicted based on the chemical composition of the fly ash.

Leaching from Fly Ash

The total metals content for a specific ash source depends on the composition of the coal. The potential for leaching of these metals not only depends on the total metals content but also influenced by the crystallinity of the fly ash, as this would dictate whether the metals are incorporated within the glasseous phase or within crystalline compounds, which will hydrate (ACAA). The metals in the glasseous phase are expected to leach at much lower rate than that from the crystalline phase.

Since the degree of crystallinity is a function of boiler design and remains relatively constant for a given source, leachable materials remain relatively constant for a given ash source. A number of state regulatory agencies have issued source approval for specific generating facilities after the consistency of these materials had been demonstrated.

For stabilized soil, the leachability of metals not only depends on the property of the fly ash but also the soil that are used for stabilized soil. Some part of these metals leached from the fly ash will be adsorbed on the clay minerals of the soil.

What is Silica?

blok21 — Tue, 20 Jan 2009 05:38:42 +0000

Silica is the name given to a group of minerals composed of silicon and oxygen, the two most abundant elements in the earth’s crust. Silica is found commonly in the crystalline state and rarely in an amorphous state. It is composed of one atom of silicon and two atoms of oxygen resulting in the chemical formula SiO_2.

The first industrial uses of crystalline silica were probably related to metallurgical and glass making activities in three to five thousand years BC. It has continued to support human progress throughout history, being a key raw material in the industrial development of the world especially in the glass, foundry and ceramics industries. Silica contributes to today’s information technology revolution being used in the plastics of computer mouses and providing the raw material for silicon chips.

Geology and occurrence of industrial silica

Silica exists in nine different crystalline forms or polymorphs with the three main forms being quartz, which is by far the most common, tridymite and cristobalite. It also occurs in a number of cryptocrystalline forms. Fibrous forms have the general name chalcedony and include semi-precious stone versions such as agate, onyx and carnelian. Granular varieties include jasper and flint. There are also anhydrous forms – diatomite and opal.

Quartz is the second most common mineral in the earth’s crust. It is found in all three of the earths rock types – igneous, metamorphic and sedimentary. It is particularly prevalent in sedimentary rocks since it is extremely resistant to physical and chemical breakdown by the weathering process. Since it is so abundant, quartz is present in nearly all mining operations. It is present in the host rock, in the ore being mined, as well as in the soil and surface materials above the bedrock, which are called the overburden.

Most of the products sold for industrial use are termed silica sand. The word “sand” denotes a material whose grain size distribution falls within the range 0.06-2.00 millimetres. The silica in the sand will normally be in the crystalline form of quartz. For industrial use, pure deposits of silica capable of yielding products of at least 95% SiO₂ are required. Often much higher purity values are needed. Silica sand may be produced from sandstones, quartzite and loosely cemented or unconsolidated sand deposits. High grade silica is normally found in unconsolidated deposits below thin layers of overburden. It is also found as “veins” of quartz within other rocks and these veins can be many metres thick. On occasions, extremely high purity quartz in lump form is required and this is produced from quartzite rock. Silica is usually exploited by quarrying and it is rare for it to be extracted by underground mining.

Physical and chemical properties

The three major forms of crystalline silica -quartz, tridymite and cristobalite- are stable at different temperatures and have subdivisions. For instance, geologists distinguish between alpha and beta quartz. When low temperature alpha quartz is heated at atmospheric pressure it changes to beta quartz at 573^oC. At 870^oC tridymite is formed and cristobalite is formed at 1470^oC. The melting point of silica is 1610^oC, which is higher than iron, copper and aluminium, and is one reason why it is used to produce moulds and cores for the production of metal castings.

The crystalline structure of quartz is based on four oxygen atoms linked together to form a three-dimensional shape called a tetrahedron with one silicon atom at its centre. Myriads of these tetrahedrons are joined together by sharing one another’s corner oxygen atoms to form a quartz crystal.

Quartz is usually colourless or white but is frequently coloured by impurities, such as iron, and may then be any colour. Quartz may be transparent to translucent, hence its use in glassmaking, and have a vitreous lustre.

Quartz is a hard mineral owing to the strength of the bonds between the atoms and it will scratch glass. It is also relatively inert and does not react with dilute acid. These are prized qualities in various industrial uses.

Depending on how the silica deposit was formed, quartz grains may be sharp and angular, sub-angular, sub-rounded or rounded. Foundry and filtration applications require sub-rounded or rounded grains for best performance.

Processing technologies

Silica deposits are normally exploited by quarrying and the material extracted may undergo considerable processing before sale. The objectives of processing are to clean the quartz grains and increase the percentage of silica present, to produce the optimum size distribution of product depending upon end use and to reduce the amount of impurities, especially iron and chromium, which colour glass.

Cleaning the quartz grains and increasing silica content is achieved by washing to remove clay minerals and scrubbing by attrition between particles. Production of the optimum size distribution is achieved by screening to remove unwanted coarse particles and classification in an upward current of water to remove unwanted fine material. Quartz grains are often iron stained and the staining may be removed or reduced by chemical reaction involving sulphuric acid at different temperatures. Impurities present as separate mineral particles may be removed by various processes including gravity separation, froth flotation and magnetic separation. For the highest purity, for electronics applications, extra cleaning with aggressive acids such as hydrofluoric acid combined with thermal shock may be necessary.

After processing, the sand may be dried and some applications require it to be ground in ball mills to produce a very fine material, called silica flour. Also, quartz may be converted to cristobalite in a rotary kiln at high temperature, with the assistance of a catalyst. Some specialist applications require the quartz to be melted in electric arc furnaces followed by cooling and grinding to produce fused silica.

Industrial Silica Applications

Silica has played a continuous part in man’s development and been one of the basic raw materials supporting the industrial revolution (as refractory, flux, and moulding sand) and today’s information technology revolution (providing the raw material for silicon chips).

Industrial silica is used in a vast array of industries, the main ones being the glass, foundries, construction, ceramics, and the chemical industry.

Silica in its finest form is also used as functional filler for paints, plastics, rubber, and silica sand is used in water filtration and agriculture.

Other examples of everyday uses include the construction and maintenance of an extensive range of sports and leisure facilities.

Crystalline silica is also irreplaceable in a series of high-tech applications, for example in optical data transmission fibres and precision casting. It is also used in the metallurgical industry as the raw material for silicon metal and ferrosilicon production. Another specialized application is in the oil production.

Altogether there are several hundreds of applications of industrial silica in our daily life. Silica products have become so obvious to us that we don’t even know they are being applied. Reading this page, you will be surprised to find out how many times per day you see, touch and use products containing crystalline silica.

For more information on the socio-economic aspects related to industrial silica uses, please have a look into the Socio – Economic Review of Crystalline Silica Usage, Brian Coope, September 1997, whose conclusion is that if man wishes to live in silica free environment he must move to another planet.

Glass Industry

Silica is the main ingredient of this vital material. The glass products containing silica include containers (bottles, jars, drinking vessels), flat glass (for windows, automotive glass, mirrors, etc.), decorative glass (glasses, decanters, bowls, figurines), fibreglass (reinforcing and insulating), technical glass (screens), and optical glass (spectacles and binoculars).

Foundries

Quartz sand is a basic material for the production of moulds and cores in metal casting. It is also used for precision casting, dental applications and jewellery casting.

Building and construction

The construction industry is by far the largest volume consumer of silica minerals. Industrial silica is used in construction aggregates, in concrete, dimension stone, masonry mortars, tile glues, floor screeds, cement manufacture, road line markings, asphalt, in bridge and sewer refurbishment, in decorative bricks, not to mention in glass and steel structures.

Ceramics

Industrial silica is a structural ingredient of clay bodies and a major constitutent of ceramic glazes, ranging from refractory bricks to wall bricks, and from sanitaryware to tableware and tiles.

Chemical industry

Quartz derivatives are used in many areas, such as pesticides, fertilisers and pharmaceuticals preparations. Another derivative from industrial silica is silicon carbide, which is the raw materials for abrasives, anti-slip and polishing products.

Functional fillers

for paints, plastics, rubber, sealants

Silica in its finest forms find important usage as reinforcing filler for use in paint, plastics, rubber, and sealants.
In paints, silica is used to render the paint more resistant to chemicals and for enhancing hardness and wear resistance.

Ultrafine silica displays strong reinforcing properties in rubber formulations and is thus a major ingredient in car tyres. Silica is also used in plastics to impart flexural and compressive strenght.

Water filtration

Silica sand is the principal filtration medium used by the water industry to extract solid impurities from waste water.

Water industries in Europe use millions of tonnes of filtration sands each year.

Agriculture

Silica sand is used in farming, market gardening, horticulture, aquaculture, and forestry, in applications ranging from soil additive, surfacing material, and animal feed material.

Sports and leisure facilities

Silica sand with soil is used in the manufacture of football and other sports pitches and golf courses.
It is also used, often with polypropylene fibre or with rubber, for all-weather horse racing tracks, show jumping rings, dog racing tracks and equestrian training areas.

Silicon metal and ferrosilicon production

Quartz and the carbon reducing agents (wood, coal, coke, charcoal, electrodes) are put in an oven heated at a very high temperature (> 2000°C) thanks to an electric arc created through the electrodes. The metal is then cast, cooled and adapted according to the refining, granulometric and packaging specifications required by the customer.

In our daily lives, Silicon is the raw material for the following applications:

Silicones and silanes used for their waterproofness, for glues and mastics’ adhesion, for their insulating properties and for moulds’ production.

Iron and steel metallurgy: silicon is used to produce special up-market steels.

High-performance concrete: reinforcing concrete’s mechanical characteristics (e.g. resistance to compression).

Electronics: highly purified silicon gives birth to micro chips through high-tech and ultra automated processes.

Aluminium alloys: silicon increases the cast flow and the mechanical properties of aluminium alloys.

Oil production

Closely sized grades of silica sand, with rounded to sub rounded particles, are used to stimulate oil well production. The sand is pumped into the oil bearing strata and increases its permeability thereby promoting the flow of oil into the well.

Mining as a Basic Industry

blok21 — Tue, 20 Jan 2009 04:58:23 +0000

Mining and Agriculture are 2 basic industries which led to the development of modern civilization.
Other basic industries include farming and fishing and more recently manufacturing.
Agriculture gives us chiefly our food and the materials from which clothes and some of our buildings are made.
Mining supplies us with :
structural material, such as stone, glass sand, clays and cement fuels, natural gas, coal and petroleum abrasives, such as garnet and corundum fertilizers, potash, phosphates and nitrates various industrial uses, such as sulfur, graphite, borax, and asbestos metallic minerals, gold, silver, copper, lead, zinc, iron and aluminum precious stones, diamonds, rubies and sapphires fissionable materials
rare metals.
From these substances come the materials which are of such vital importance in time of war and which, in times of peace, are so necessary for the growth of our arts, sciences and industry.

National Importance
The importance of minerals to national security was firmly established during World War I. When the free world entered into the conflict in 1917, the most serious question that arose in conducting war was the shortage of ships for supplying food and fuel and especially the minerals needed for manufacture of explosives and other products necessary for the prosecution of war.
Along with war minerals, fuels and iron held positions of greatest importance. Fortunately, the allies had large reserves of these fuels, especially coal, which is of greater commercial value than iron and steel. So valuable was coal, that laws were established for the purpose of controlling the transportation and distribution of coal throughout the free world. Oil was also conserved by eliminating unnecessary hauls and waste.

Mineral Resources and International Relations
The importance of international negotiations to a country whose reserves of necessary minerals has been depleted is obvious. Mines are WASTING ASSETS and a country once rich in minerals may later be compelled to import these essential materials. For any nation, a well balanced supply of minerals is better than a supply of some and a lack of others. Of these resources, the mineral fuels and iron are of primary importance. Copper, lead, and zinc come next. With them should be ranked the fertilizer group of phosphates, potash and nitrates together with sulfur, of so much importance in the chemical industries. Gold and silver are of little importance in building up industrial development.

Nickel, manganese, fluorspar, vanadium, tungsten and other mineral products – asbestos, mica, mercury, graphite, antimony and tin – are needed in industry. However, the quantities required are small and can be transported long distances to industrial centers. Industrial nations must have secure access to such resources and their control is a matter of international concern.
Most industrial nations lack sufficient resources to be self-sufficient and normally STOCKPILE the necessary mineral raw resources. Under the urge of economic nationalism, there has been a multiplication of production in the mineral industry throughout the world, not because of a shortage of world supply but through fear of being at the mercy of another nation in times of emergency.

Mining Communities
Well over 100 communities across Canada with a total population of over 600 000 are dependent on the minerals industry. These communities are located in all regions of the country, but mainly in remote and rural areas. The population of these dependent communities ranges in size from a few hundred people (for example, Ming’s Bight, Newfoundland, and Nanisivik, Nunavut) to much larger communities with populations in the tens of thousands (for example, Rouyn-Noranda, Quebec, and Timmins, Ontario).
In other Canadian communities, such as Sudbury, the minerals industry is an integral part of their diversified economy. And a number of communities depend on a combination of natural resource industries — energy, forestry and minerals. For example, Hinton,Alberta, has ties to the mining, forestry and energy sectors. The urban centres of Toronto, Montreal and Vancouver are home to many of the financial services used by the minerals industry, including those provided by stock exchanges, underwriters and brokerage houses. In addition many mining companies have their headquarters in these urban centres.

Over 2200 Canadian-based companies sell specialized scientific or technical products for use by mining companies operating in Canada. Suppliers of mining goods and services are located in more than 400 communities across Canada. Firms in Toronto,Vancouver and Sudbury account for 45% of goods supplied to mining companies. Mining companies tend to purchase a significant portion (over one third) of their goods and materials from suppliers within an 80-km radius of their operations. The minerals industry holds the promise of economic development opportunities for the Aboriginal population, as approximately 1200 Aboriginal communities are located within 200 km of mineral ands metals activities.
The Canadian non-fuel minerals industry continues to make an important contribution to Canada’s economy: it contributes almost 4% of the national GDP. The minerals industry provides some of the highest weekly earnings in the economy — averaging over $1000: this far surpasses the average weekly earnings across the Canadian economy, which are about $600. Employment in the minerals industry remains a source of strength in the Canadian economy.

In 2000, approximately 53 000 Canadians were directly employed in the mining industry and about another 350 000 were employed in the downstream minerals industry. Canada Resources naturelles Canada Natural Resources Canada The Importance of Mining to Canadian Communities Many communities in Canada have an important stake in the future of this nation’s minerals industry. Natural Resources Canada recognizes the importance of the minerals industry to Canadian communities.

MINERAL NAMES

blok21 — Tue, 20 Jan 2009 04:25:39 +0000

*Mineral/rock*	*Derived from or for*
Actinolite	Greek actino = ray and lithos = stone in reference to its occurrence in bundles of radiating needles
Agalmatolite	Greek algalma = image and lithos = stone as it was carved by the Chinese
Agate	locality at the River Achates, now Drillo in Sicily, where it was originally found
Aggregate	Latin aggregatus = to lead to a flock, add to
Akageneite	locality at Akagame mine, Iwate Prefecture, Japan
Alabandite	locality at Alabanda in Caria, Asia Minor
Alabaster	ancient ointment jars called alabastra and perhaps Alabastron in Egypt; alternatively from Egyptian a-la-baste = ship of the Goddess Ebaste = Bubaste
Albite	Latin albus = white, for its color
Alexandrite	Czar Alexander II (1818-1881) of Russia
Allanite	Thomas Allan (1777-1833), Scottish mineralogist and first observer
Almandine (garnet)	Alabanda, Asia Minor, where garnets were cut and polished
Aluminum	Latin alumen = alum, original name for natural aluminum sulfate
Alunite	Latin alumen = alum (see above) and French alun = alum
Amazonite	locality at Amazon River, South America
Amber	French ambre from Arabic anbar = ambergris (now obsolete)
Amblygonite	Greek amblys = dull, obtuse and gonia = angle, in reference to cleavage angle
Amethyst	Latin amethystus and Greek amethystos = not drunken as the stone and plant was thought to orevent intoxication
Amosite	acronym of Asbestos Mines of South Africa
Analcime	Greek analkis = without strength due to its weak electrical properties when heated or rubbed
Anatase	Greek anatasis = extension because of the greater length of the common pyramid as compared with other tetragonal minerals
Andradite (garnet)	J.B.d’Andrada e Silva (1763-1838), Brazilian mineralogist and first observer
Anhydrite	Greek anhydros = dry or without water
Anorthite	Greek for not straight, because of its triclinic symmetry
Antimony	Latin from Greek anti = against plus monos = a metal seldom found alone
Andalusite	locality at Andalusia, Spain
Anthophyllite	neo-Latin anthophyllum = clove for its brown color, Greek lithos = stone
Apatite	Greek apate = deceit since it was often mistaken for other minerals
Aphthitalite	Greek aphthitos = unchangeable or indestructible, alis = salt, and lithos = stone since it is very stable in air
Aquamarine	Latin aqua marina = seawater alluding to its pale bluish-green color
Aragonite	locality at Aragon, Spain, where it was first identified
Arcanite	Medieval Latin alchemical name, Arcanum duplicatum = double secret
Asbestos	Latin and Greek asbestos = inextinguishable alluding to its early uses as a wick
Ascherite	a.k.a Szaibelyle
Atacamite	locality at Atacama Desert, Chile
Attapulgite	locality at Attapulgus, Georgia, USA
Axinite	Greek axine = ax in reference to its wedge-shaped crystals
Azoproit	Russian title for the International Association for the Study of Deep Zones of the Earth’s Crust (AZOPRO) since it was found during the preparation of a guidebook for the Association’s meeting in Baikal in 1969
Baddeleyite	Joseph Baddeley who brought the original specimens from Sri Lanka
Ball clay	from the tradition of rolling the clay to the cart and thus forming a “ball” weighing 13-22 kg (30-50 lb) with a diameter of about 25 cm (10 inches)
Barite	Greek barys = heavy or dense
Barylite	Greek barys = heavy or dense, lithos = stone
Bassanite	locality at Basset group of mines, Redruth, Cornwall, England
Bastnaesite	locality at Bastnäs, Vastmanland, Sweden
Bauxite	locality at Les Baux, near Arles, France where it was discovered by P. Berthierin
Beidellite	locality at Beidell, Colorado
Bementite	Clarence Sweet Bement (1843-1923), American machine tool manufacturer from Philadelphia; collector of coins, books, and minerals
Benstonite	for O.J. Benston (1901- ), American ore dressing metallurgist, National Lead Company, Malvern, AR, who provided specimens for initial study
Bentonite	for the Benton Shale named for Fort Benton, Montana, United States (originally named Taylorite for Taylor Ranch, the site of the first mine near Rock River, Wyoming, which opened in 1888)
Bertrandite	Marcel Alexandre Bertrand (1847-1907), French mineralogist
Beryl	Greek beryllos of uncertain etymology applied to beryl and green gems
Beryllium	beryl (see above), the mineral from which it was isolated
Bikitaite	locality at Bikita, Zimbabwe
Biotite	Jean Baptiste Biot (1774-1862), French physicist who studied its optical aspects
Birnessite	locality at Birness, Scotland
Bischofite	Gustav Bischof (1792-1870), German chemist and geologist
Bixbyite	Maynard Bixby of Salt Lake City, UT, who compiled a catalog of Utah minerals
Blanc fixe	French blanc = white and fixe = settled referring to the barium sulfate precipitate
Bloedite	Carl August Bloede (1773-1820), German chemist
Boehmite	Johannes Böhm (1857-1938), German geologist and first observer
Boracite	derived from borax (see below). A.k.a.
Borax	Persian burah and Arabic buraq, both old names for the mineral. A.k.a. tincal.
Bradleyite	Wilmot Hyde Bradley (b. 1899), American geologist, USGS
Brannerite	John Casper Branner (1850-1922), American geologist
Braunite	Kammerath Braun, of Gotha, Germany
Brazilianite	Brazil, where the mineral was first found
Bromine	Greek bromos = stench in reference to its characteristic odor
Bromargyrite	Greek bromos = stench and argyros = silver alluding to to composition
Brookite	Henry James Brooke (1771-1857), English mineralogist
Brucite	Archibald Bruce (1777-1818), American mineralogist and first observer
Brüggenite	Juan Brüggen (1887-1953), Chilean geologist
Burkeite	William Edmund Burke (1980-), American chemical engineer
Cahnite	Lazard Cahn (1865-1940), American mineral collector who first recognized the mineral in Franklin, New Jersey.
Cairngorm	locality at Cairngorm, southwest of Banff, Scotland
Calcite	Latin calx, calcis = lime; this is the same origin for chalk and limestone
Carnallite	Rudolph von Carnall (1804-1874), Prussian mining engineer, Greek lithos = stone
Celestite	Latin caelestis = heavenly for its faint blue color
Cement	Old French ciment from Latin caementum = chip of stone used to fill up in building a wall
Cerite/Cerium	after Ceris, an asteroid discovered in 1803
Chabazite (zeolite)	Greek chabazios or chalazios, an ancient name of a stone celebrated in a poem ascribed to Orpheus
Chalcedony	from Chalcedon or Calchedon, an ancient maritime city of Bithynia on the Sea of Marmara in modern Turkey
Chalcophanite	Greek chalcos = copper and to appear refering to the change of color on ignition
Chalcopyrite	Greek chalcos = copper and its similarity with pyrite.
Chaistolite (variety of andalusite)	Greek chiastos = marked with a chi (x) and lithos = stone alluding to the cross exhibited in transverse sections
China clay	commercial term for kaolin which was named for Kau-ling in China
Chiolite	Greek = snow alluding to its appearance and similarity to cryolite (ice)
Chlorite	Greek chloros = light green in reference to its color
Chromite	Greek chroma = a color for the brilliant hues of its compounds
Chrysoberyl	Greek chrysos = golden or yellow plus beryllos = beryl
Chrysolite	Greek chrysos = golden or yellow plus lithos = stone
Chrysoprase	Greek chrysos = golden or yellow plus prason = leek alluding to green color
Chrysotile	Greek chrysotos = guilded in reference to its color and nature
Citrine	Latin citrus or French citron = lemon in reference to its yellow color
Clinoenstatite	Greek klinein = to bend or slope (monoclinic diomorph) of enstates = an adversary because of its refractory nature
Clinoptilolite	Greek klinein = to bend or slope, monoclinic Greek for wing or down alluding to its light nature, and lithos = stone
Colemanite	William Tell Coleman (1824-1893), a borate developer in California
Cordierite	Pierre Louis A. Cordier (1777-1861), French mining engineer & geologist
Coronadite	for Francisco Vasquez de Coronado (ca. 1500-1554), Spanish explorer of SW America
Corundum	Hindi kurund, or the Tamil kurundam, describing a native stone of India
Crandallite	Milan L. Crandell Jr., American engineer, Knight Syndicate, Provo, Utah and Greek lithos = stone
Cristobalite	Cerro San Cristóbal near Pachuca, Mexico and Greek lithos = stone
Crocidolite	Greek krokis or krokidos = the nap on cloth and lithos = stone
Cryolite	Greek kryos = cold, frost and lithos = stone for its icy appearance
Cryptomelane	Greek kryptos = hidden, secret and melas = black in reference to the difficulty of identifying it as a species and its color
Danburite	locality at Danbury, Connecticut
D’ Ansite	Jean D’ Ans (1881- ), German chemist, professor, Berlin
Darapskite	for Ludwig Darapsky (1857-?), mineralogist and chemist from Santiago, Chile
Datolite	Greek = to divide due to granular character of some varieties
Dawsonite	John William Dawson (1820-1899), Canadian geologist, principal of McGill University, Montreal, Canada
Diamond	Latin adamas = unconquerable or invincible; first used in Manilius (AD 16)
Diaspore	Greek dia = through and speirein = to scatter in reference to its characteristic decrepitation on heating
Dickite	Allan Brugh Dick (1833-1926), Scottish metallurgical chemist
Diatomite	Latin from Greek dia = through and tome = cutting in reference to the two generally symmetrical valves of the single-cell diatom
Dietzeite	August Dietze (?-1893?), who first described the mineral
Diopside	Greek diopsis = to view through since it is usually transparent
Dolomite	Deodat Guy Silvain Tancrède Gratet de Dolomieu, French geologist
Dumortierite	Eugène Dumortier (1802-1873), French paleontologist
Dunite	named for its type locality at Dun Mountain, Nelson, New Zealand
Dysprosium	Greek dysprositos = hard to get at in reference to the difficulty of separation
Embolite	Greek embole = insert and lithos = stone since it contains both the chloride and bromide of silver
Emerald	Latin smaragdus and Greek smaragdos = emerald, probably of Semitic origin; ancient name applied to a variety of green minerals
Emery	French emeri, Italian smeriglio, and Greek smiris or smeris; akin to the Greek myron = urgent
Epsomite	locality at Epsom, a town near London, England
Erionite (zeolite)	Greek erion = wool alluding to its white wool-like appearance
Euclase	Greek eu = good, well and klasis = a breaking due to its easy cleavage
Eucryplite	Greek eu = good, and concealed due to its mode of occurrence embedded in albite
Eudialyte	Greek eu = good, well and dialytos = capable of dissolution
Eudidymite	Greek eu = good, well and twin, due to the twinned crystal
Eugsterite (Fritzshe’s salt)	N.A.
Europium	Continent of Europe named for Europa, daughter of a king of Phoenicia
Euxenite	Greek for friendly to strangers or hospitable referring to the rare-earth elements it contains
Faujasite (zeolite)	Barthélemy Faujas de Saint Fond (1741-1819), French geologist
Fayalite	locality at Fayal Island in the Azores and Greek lithos = stone
Feitknechtite	for Walter Feitknecht (1899- ), University of Bern, who first synthesized the compound
Feldspar	Swedish feldt or fält = field and spat = spar, for the spar in the tilled fields overlying granite
Fergusonite	Robert Ferguson (1799-1865), Scottish physician
Ferrierite (zeolite)	Walter Frederick Ferrier (1865-1950), Canadian geologist and moning engineer
Ferronatrite	Latin ferrum = iron and natrium = soda describing its composition
Flint	Greek plinthos = a brick
Florencite	Willian Florence (1964-1942), Brazilian mineralogist who studied minerals in Minas Gerais
Fluoborite	from composition, a fluoborate of magnesium
Fluocerite	containing fluorine and cerium named for Ceris, an asteroid
Fluorapatite	containing fluorine and apatite
Fluorite	Latin fluere = flow, then German flüssen = fuse (German flussspat)
Forsterite	Adolarius Jacob Forster (1739-1806), English mineral collector
Francolite	Wheal (= mine) Franco, Tavistock in Devon, England, Greek lithos = stone
Fuller’s earth	clay used by the fuller to degrease cloth in a process known as fulling
Furgusonite
Gadolinite	Johan Gadolin (1760-1852), Finnish chemist and discoverer of yttrium
Galena	Latin galena = lead ore or dross remaining after melting lead
Garnet	Latin granatum = a pomegranate since it RESEMBLes their red seeds; alternatively Latin granatus = like a grain since it RESEMBLes seeds or grains embeded in the matrix
Gaylussite	Joseph Louis Gay-Lussac (1778-1850), French chemist, Greek lithos = stone
Gibbsite	George Gibbs (1776-1833), owner of the mineral collection acquired by Yale early in the 19th century
Glaserite	???
Glauberite	Johann Wilhelm Glauber (1603-1668), German chemist
Glauconite	Greek glaucos = originally gleaming, later bluish green, silvery, or gray
Goethite	Johann Wolfgang von Goethe (1749-1832), German poet/philosopher
Graphite	Greek for graphein = to write due to its use in making pencils
Grossularite (garnet)	Latin grossularium = gooseberry for its pale green color
Groutite	Frank Fitch Grout (1880-1958), American petrologist, U of Minnesota
Guano	Indian huanu = dung
Gypsum	from the Greek gypsos = plaster, an ancient name
Hafnium	Latin Hafnia = ancient name for Copenhagen
Halite	Greek hals = the sea (see salt)
Halloysite	Baron Omalius d’Halloy (1707-1789), Belgian geologist and first observer
Hanksite	Henry Garber Hanks (1826-1907), State Mineralogist of California
Hausmannite	Johann Friedrich Ludwig Hausmann (1782-1859), German mineralogist
Hectorite	locality at Hector, California, USA
Heliodor	Greek helios = sun — “gift of the sun”.
Helvite	Greek helvus = light yellow alluding to the mineral’s color
Hematite	Greek haimatites = bloodlike alluding to its red color
Hessonite	Greek ésson = inferior in reference to its inferior hardness and color
Heulandite	John Henry Heuland (1778-1856), English mineral collector
Hiddenite	A.E. Hidden, mine owner and first observer
Hollandite	Thomas Henry Holland (1868-1947), British geologist, Director of Geol. Survey of India
Holmium	Latin Holmia = ancient name for Stockholm
Howlite	Henry How (1828-1879), Canadian chemist and first observer
Huntite	Walter Frederick Hunt (1882-1975), American mineralogist, U of Michigan, Ann Arbor
Hydroboracite	Greek hydor = water plus boracite
Illite	locality in the state of Illinois, USA
Ilmenite	locality at the Ilmen Mountains, former USSR, where it was first located
Inderborite	Inder Lake, western Kazakhstan and composition of borate.
Inderite	Inder Lake, western Kazakhstan
Inyoite	Inyo County, California
Iodine	Greek iodes = violet alluding to its color
Jacobsite	locality at Jacobsberg, Wermland, Sweden
Jade/jadeite	Spanish term piedra de yjada = stone of the side since the stone was supposed to cure side pains
Jarosite	Jaroso Ravine in the Sierra Almagrera, Spain
Jasper	Latin iaspis, which is of oriental origin, equivalent to the Persian iashm and jashp and the Assyrian ashpu
Kainite	Greek kainos = new, recent alluding to its recent (secondary) formation
Kaliborite	composition, kalium = potassium, and boron = borate
Kandite	comprising the minerals kaolinite, nacrite, and dickite
Kaolin	Chinese Kau-ling = high ridge, a village in northwest Jiangxi Province, China, where deposits of white kaolin have long been exploited to make fine white porcelain known as china (see china clay)
Kermesite	from kermes, a name given in old chemistryto red amorphous antiminy trisulfide often mixed with antimony trioxide
Kernite	locality at Kern County, California
Kieselguhr	German kiesel = flint and guhr = earthy sediment deposited in water
Kieserite	Dietrich Georg Kieser (1779-1862), President of Jena Acadamy, Germany
Kornerupine	Andreas Nikolaus Kornerup (1857-1881), Danish geologist
Kotoite	Bundjirom Koto (1856-1935), Japanese geologist and petrographer, U of Tokyo
Kramerite	locality at Kramer boron deposit, California. A.k.a. probertite.
Kurnakovite	Nikolai Semenovich Kurnakov (1860-1941), Russian mineralogist
Kunzite	G.F. Kunz, American mineralogist
Kyanite	Greek kyanos = dark blue reflecting its color
Labradorite	the mineral was first brought from the Isle of Paul, Labrador, about 1770
Langbeinite	A. Langbein, German chemist of Leopoldshall
Lanthanum	Greek lanthanein = to be unseen, unnoticed, or concealed
Lapis lazuli	Latin lapis = a stone and Persian lazhward = blue color
Laumontite (zeolite)	François Pierre Nicolas Giller de Laumont (1747-1834), French discoverer
Lautarite	locality at Oficina Lautaro, Antofagasta Province, Chile
Lecontite	John Lawrence LeConte (1825-1883), American entomologist of Philadelphia who discovered the mineral
Leonite	Leo Strippelmann, director of the salt work at Westerregeln, Germany
Lepidocrocite	Greek lepis = scale in reference to the scaly or feathery habit, and (Latin) crocinus = saffron, golden, yellow for its color
Lepidolite	Greek lepis = scale and lithos = stone because of its micaceous structure
Leucite	Greek leukos = white reflecting its whire or gray color
Leucoxene	Greek leukos = white and xenos = stranger alluding to its color and secondary nature
Lime	Old English; related to Dutch iljm & Latin limus = mud, linere = to smear
Limonite	Greek leimon = meadow since it often occurs in bogs and swamps
Lithiophilite	Greek lithos = stone and philos = loving alluding to its composition
Lithiophorite	Greek lithos = stone and to bear in reference to its lithium content
Lithium	Greek lithos = stone
Loeweite	Alexander Loewe (1808-1846), German chemist
Loparite	Russian name for the Lapp inhabitants of the Kola Peninsula
Ludwigite	Ernst Ludwig (1842-1915), Austrian chemist, U of Vienna
Lutetium	Lutetia, the ancient name for Paris
Maghemite	from the fisrt syllables of magmetite and hematite referring to the magnetism and and composition
Magnesite	see magnesium; applied to a series of magnesium salts by J.C. Delanethrie in 1795; D.L.G. Karsten first restricted it to the natural carbonate in 1808
Magnesium/ magnesia	Possibly Latin magnesia, a mineral said to be brought from the province of Magnesia in Thessaly, Greece > magnesia alba > “magnesia” and “magnesium” (magnesia negra > “manganese”); See manganese.
Magnetite	Middle Latin magnes = magnet in reference to its magnetic properties; or from Magnes, a shepherd who first discovered the mineral on Mount Ida when the rock was attracted to the nails in his shoes
Manganese	Possibly Latin magnesia, a mineral said to be brought from the province of Magnesia in Thessaly, Greece > magnesia negra and corrupted to “manganese” (in common with magnesia alba > “magnesia” and “magnesium”; alternatively Greek mangania = magic. See magnesium/magnesia.
Manganite	manganese content (see above)
Marble	Greek marmairein = to shine, marmaros = white glistening stone
Marcasite	probably Arabic or Moorish for pyrite and similar substances
Mayenite	locality near Mayen, Eifel district Rhineland-Palatinate, Germany
Meerschaum	Greek meer = sea and schaum = froth for its light weight and color
Mendozite	Mendoza, Argentina
Meyerhofferite	Wilhelm Meyerhoffer (1864-1906), German chemist
Mica	Latin micare = to shine or to glitter or the Latin mica = a crumb or grain
Microcline	Greek mikro = little and klinein = to incline in reference to its characteristic variation of cleavage angle from 90^o
Millisite	F.T. Mills, of Lehi, Utah, the first observer
Mirabilite	Latin sal mirabilis = wonderful salt, Greek lithos = stone
Mohavite	Mohave desert, California. A.k.a. tincalconite.
Monazite	Greek monazein = to be alone alluding to its rarity
Montebrasite	locality at Mintebras, Creuse, France
Montmorillonite	locality at Montmorillon, Vienne, France
Mordenite (zeolite)	Morden, King’s County, Nova Scotia, Canada
Morganite	John Pierpont Morgan, American banker and gem enthusiast
Mullite	locality at the island of Mull, Scotland, Greek lithos = stone
Muscovite	Muscovy glass, when first described from Muscovy Province, Russia
Nahcolite	acronym of Na, H, C, O plus Greek lithos = stone
Natrolite (zeolite)	Latin natrium or Greek natron = native soda plus lithos = stone
Natron	Latin natrium or Greek nitron = native soda
Neodymium	Greek neos = new and didymos = twin
Nepheline	Greek nephele = cloud alluding to the cloudy appearance developed on immersing nepheline in strong acid
Nephrite	Latin lapis nephriticus = kidney stone since it was often worn to remedy diseases of the kidnies
Nesquehonite	Nesquehoning near Lansford, Carbon County, Pennsylvania
Niter/Nitrates	ancient origin: Latin nitrum, the Greek for nitron, the Hebrew nether; perhaps originally from Nitria, a city in Upper Egypt
Nontronite	locality at Arrondissement of Nontron, near the village of Saint Pardoux, France
Northupite	Charles H. Northup (b. 1861), American grocer and first observer
Novaculite	Latin novacula = razor hone alluding to its use as a sharpening stone
Nsutite	locality at the Nsuta Mine, Ghana
Ochre	Latin and Greek ochra = pale or pale yellow alluding to its color
Offertite (zeolite)	Albert Jules Joseph Offret (1857-?), professor, Lyons, France
Olivine	Latin oliva = olive alluding to its olive green color
Onyx	Greek onyx = claw, fingernail, hoof in reference to the color
Opal	from Sanskrit upala = stone or precious stone
Orthoclase	Greek for straight and klasis = fracture in reference to its cleavage angle of 90°
Palygorskite	locality at “in der Paligorischen Distanz” of the second mine on the Popovka River, Urals, former USSR, where it was observed
Pandermite	locality at Panderma, the old name for Bandirma, a port in Turkey
Parisite	J.J. Paris, proprietor of the mine at Muzo, north of Bogata, Colombia, where the mineral was discovered
Peat	Anglo-Latin peta = piece of turf
Pentlandite	Joseph Barclay Pentland (1797-1873), Irish natural scientist and traveler
Periclase	Greek peri = around and klasis = fracture due to its perfect cubic cleavage
Peridot	French péridot of unknown origin
Perlite	French perle = pearl due to its pearly luster and form when hammered
Perovskite
Petalite	Greek petalon = leaf and lithos = stone alluding to its leaflike cleavage
Phenak(c)ite	Greek phenax = to cheat since it was often mistaken for quartz
Phengite	Greek and Latin phengites = shine in reference to its luster
Phillipsite (zeolite)	William Phillips (1775-1829), British mineralogist, founder of the Geological Society of London
Phlogopite	Greek phlogistos = to burn or inflame alluding to its reddish tinge
Phonolite	Greek phone = sound and lithos = stone in reference to its ring when struck with a hammer
Phosphate	Greek for phos = light and phoros = bearer due to its spontaneous combustion; frpm the Latin meaning morning star
Pinnoite	Mt. Pinno, Chief Councellor of Mines, of Halle, Germany
Pirssonite	Louis Valentine Pirsson (1860-1919), American mineralogist at Yale
Plagioclase	Greek plagios = oblique and klasis = fracture in reference to the oblique angles between its best cleavages
Plumbago	Latin plumbum = lead since graphite was misidentified as galena
Pinite
Polianite	N.A.
Pollucite	Pollux, the twin brother of Castor in Classical mythology, in reference to its association with the mineral castor (old name for petalite)
Polyhalite	Greek polys = much or many and hals = salt due to the component salts
Portland cement	resembles a building stone on the Isle of Portland, Dorset, England
Portlandite	from Portland cement, locality at the Isle of Portland, Dorset, England, with which the synthetic compound was known to be associated
Potash	from pot and ash, originally prepared by evaporating the lixivium of wood ashes in iron pots (see soda ash)
Pozzalana	locality at Pozzuoli near Mount Vesuvius where a tuff was extracted by the Romans
Praeseodymium	Greek prasios = green and didymos = twin
Priceite	Thomas Price (b. 1837?), Welsh-American mineralogist. A.k.a Pandemite.
Probertite	Frank Holman Probert (1876-1940), Dean of the Mining College, U of Cal. A.k.a. kramerite.
Promethium	Prometheus, a Titan in Greek mythology, who made a man of clay from fire stolen from heaven
Psilomene	Greek psilos = naked, bare and melas = black alluding to its appearance
Pumice	Latin pumex = pumice or porous stone from spuma = foam
Pyrrhotite	Greek for redness aluding to the liveliness of its color
Pyrite	Greek pyrites = flint or millstone from pyros = a fire since it gives off sparks when struck
Pyrochlore	Greek pyros = a fire and chloros = green since it turns green on ignition
Pyrolusite	Greek pyros = a fire and lusite = to wash due to its use to decolorize glass
Pyrope (garnet)	Greek pyr = fire and ops = eye alluding to its fire-red color
Pyrophyllite	Greek for pyro = a fire, phyllo = a leaf, and lithos = stone referring to the effect of heat separating the laminae in foliated varieties
Quartz	Saxon word querkluftertz = cross-vein ore; first condensed to querertz; or West Slavic word kwardy
Ramsdellite	Lewis Stephen Ramsdell (1895-1975), American mineralogist, U of Michigan, Ann Arbor
Rare earths	named by Johann Gadolin as a literal description of a group of elements
Rhodochrosite	Greek rhodochros = rose colored alluding to its color
Rhodonite	Greek rhodon = a rose alluding to its color
Roseki	Japanese for waxy stone referring to its wax-like appearance.
Roscoelite	Henry Enfield Roscoe (1833-1915), a chemist from Manchester, England, who first to prepared pure vanadium
Ruby	Latin rubeus = red alluding to its color
Rutile	French shining from Latin rutilus = red alluding to its color
Sanbornite	for Frank Sanborn, American mineralogist. Div. Mines, Dept. Natural Resources, CA
Sanidine	Greek sanis (-idos) = a board, a table in reference to the mineral’s tabular habit
Salt	Latin sal which originated from the Greek for hals = the sea (see halite)
Samarskite	Vasilii Erafovich Samarski-Bykhovets (1803-1870), of the Russian Corps of Mining Engineers
Saponite	Latin sapo (-idos) = soap for its soaplike appearance
Sapphire	ancient name of uncertain origin; possibly Hebraic sappir and Sanskrit sanipruja; applied by the ancients to lazurite
Sassolite	Sasso, Tuscany, Italy where first observed, Greek lithos = stone
Searlesite	John W. Searles, Californian pioneer; Searles Lake, CA, named for him
Selenite	Greek selenites (lithos) = moon (stone) since it was supposed to wax and wane with the moon and/or it has moon-like white reflections
Sellaite	Quntino Sella (1827-1884), Italian mining engineer and mineralogist
Senarmonite	Henri Hureau de Sénarmont (1808-1862), French physicist and mineralogist, School of Mines, Paris, who first described the species
Sepiolite	Greek sepion = the bone of the cuttle-fish and lithos = stone since the bone of the cuttle-fish is light and porous like the mineral
Sericite	Greek for silky alluding to its silky luster
Serpentine	Latin serpens = snake because of the similar surface patterns
Shortite	Maxwell Naylor Short (1889-1952), American mineralogist, U of Arizona, and Greek lithos = stone
Siderite	Greek sideros = iron in reference to its composition
Sienna	locality at the town of Sienna in Tuscany, northern Italy
Silica	Latin silex = flint
Sillimanite	Professor Benjamin Silliman (1779-1864), American mineralogist, Yale
Slate
Smectite	Greek smektis = fuller’s earth from smechein = to wipe off, to cleanse because of its property of extracting grease from cloth (see Fuller’s Earth)
Soda	possibly from the name of a mineral that occurs near Djebel es Soda, Libya. Alternatively, the Spanish soda (from the Arabian suvvad = a plant from the ash of which soda was obtained in Sicily and Spain), or from the medieval Latin sodanum = a remedy for headaches (from the Arabic suda = headache).
Soda ash	from soda and ash, originally prepared by evaporating the lixivium of wood ashes in iron pots (see potash)
Sodalite	from composition, Latin solidus = solid since it was a solid used in glassmaking (see soda ash)
Sodium sulfate	chemical name
Spessartine (garnet)	locality at Spessart in northwestern Bavaria, Germany
Sphalerite	Greek for trecherous or slippery since it was often mistaken for galena but yielded no lead
Sphene	Greek for wedge due to characteristic habit of the crystals
Spinel	Latin spinella = little thorn referring to its spine-shaped octahedral crystals
Spodumene	Greek spodoun = to reduce to ashes refers either to its ash-gray color or the ash-colored mass formed when heated before the blowpipe
Stassfurtite	locality at Stassfurt, Germany, where it is associated with potash. A.k.a. boracite
Staurolite	Greek stauros = a cross and lithos = stone because of its common cruciform twins
Steatite	Greek steatos = suet
Stibiconite	Greek stimmi and Latin stibium = antimony and Greek for powder or dust, because it often occurs as a powder
Stibnite	Greek stimmi and Latin stibium = old names for antimony
Strontianite	locality at Strontian, a small town in Argyllshire, Scotland
Suanite	locality at Suan County, Korea
Sulfur	Latin sulfur, an old name; akin to Sanskrit sulvere
Sulphohalite	from composition, a sulfate with the halogen elements Cl and F
Suzorite	locality at Suzor Township near Boucherville, Quebec, Canada (phlogopite mica)
Sylvite	old chemical name Sal digestivus Sylvii or digestive salt of Francois Sylvius de la Boë (1614-1672), Dutch chemist and physician of Leyden
Syngenite	Greek syn = with, together with, or related to in reference to its similarity to polyhalite
Szaibelyite	Stephan Szaibely (1777-1855), Hungarian mine surveyor of Rézbánya. A.k.a. ascherite
Talc	Arabic talq
Tamarugite	locality at Tamarugal, Pampa, Chile
Tanzanite	locality at Tanzania, Africa
Tephroiite	Greek for ash-colored due to its color
Teruggite	Mario E. Teruggi, geologist, Universitatd Nacional La Plata, Argentina
Thenardite	Louis Jacques Thénard (1777-1857), French chemist, U of Paris
Thermonatrite	Greek therme = heat and natron = soda since it forms from drying soda
Thorium	Thor, Scandinavian god of thunder and lightening in reference to its use in energy
Thulite	Thule, the ancient name of Scandinavia
Tincal	Sanskrit tincal or Malay tingkal = borax. A.k.a. borax.
Tincalconite	Sanskrit tincal = borax and Greek konis = dust or powder; the fact it can form from the dehydration of borax A.k.a. mohavite.
Titanium/ titanium dioxide	Latin Titani and Greek Titanes = a Titan, in Greek mythology any one of twelve children of Uranus ( Heaven) and Gaea (Earth); denotes strength
Todorokite	locality at the Todoroki mine, Hokkaido, Japan
Topaz	from the Greek Topazion, an island in the Red Sea, meaning to seek since the island was often covered in mist
Toseki	Japanese meaning “stones used for pocelain raw material (pottery stone)
Tourmaline	Singhalese turamali = originally applied to zircon and other gems by jewelers in Sri Lanka
Tremolite	locality at Tremola Valley, near St. Gotthard, Switzerland, and Greek lithos = stone
Tridymite	Greek tridymos = threefold since the crystals are often trillings
Tripoli	locality at Tripoli, Libya, in North Africa
Trona	Arabic name of the native salt
Tsavolite	locality at Tsavo National Park, Kenya , first discovered, and Greek lithos = stone
Tunellite	George Tunell (1900- ), American geochemist, U of California, Los Angeles
Turquoise	Old French turqueise = Turkish as stones came to Europe from Persia via Turkey
Tychite	in Greek mythology Tyche = the Goddess of Chance alluding to the fact that two tychite crystals in a stock of 5,000 northupite crystals were the first and the last to be found
Tysonite	S.T. Tyson who collected and supplied the specimens in the original study
Ulexite	George Ludwig Ulex (1811-1883), German chemist and first observer
Umber	locality at the Umbria idistrict of Italy or possibly Latin umbra = a shade or shadow
Uralborite	locality at Ural Mountains in the former USSR and its borate content
Uvarovite (garnet)	Count Sergei Semeonovich Uvarov (1786-1855), Russian nobleman, Imperial Academy of St. Petersburg
Valentinite	Basilius Valentinus (pseudonym for Johannes Thölde), German alchemist working on the properties of antimony in the late 17th and early 18th century.
Vanthoffite	Jacobus Hendricus van ‘tHoff (1852-1911), Dutch physical chemist
Veatchite	Dr. John A. Veatch who first discovered boracic acid in northern Californian springs
Vermiculite	Latin vermiculare = to breed worms alluding to its appearance after exfoliation and Greek lithos = stone
Vernadite	Vladimir Ivanovich Vernadskii (1863-1945), Russian naturalist and geochemist
Vesuvianite	locality at Mt. Vesuvius, Italy, where it was found in ejected blocks
Villiaumite	French explorer Villiaume who brought the specimen from Guinea
Vonsenite	Magnus Vonsen (1879-1954), American mineral collector of Petaluma, CA, who was interested in borate minerals. A.k.a. paigeite.
Wad	provincial English word for black, soft powders of unknown origin
Wairakite	locality at Wairakei in the central part of the North Island, New Zealand
Wardite	Henry Augustus Ward (1834-1906), American naturalist, Rochester, NY
Wavellite	William Wavell (d.1829), English physician, Horwood Parish, Devon, UK, and Greek lithos = stone
Wegscheiderite	Rudolph Wegscheider, chemist who formed the compound synthetically
Witherite	William Withering (1741-1799), English physician, botanist & mineralogist
Wollastonite	William Hyde Wollaston (1766-1828), English chemist and mineralogist
Xenotime	Greek xenos = foreign, a stranger and time = to honor alluding to the fact that crystals are small and rare, and were long unnoticed; originally mispelled kenotime, Greek for vain and to honor
Ytterbium/yttrium	locality at Ytterby, Sweden
Zeolites	Greek zein = to boil and lithos = stone (i.e. boiling stones)
Zinnwaldite	locality at Zinnwald, Bohemia, itself named for the local tin (German Zinn) veins
Zircon	from Arabic zarqun, derived from the Persian zar = gold and gun = color
Zoisite	Siegmund Zois, Baron von Edelstein (1747-1819), Austrian scholar
Sources: Fleischer, M, 1975, Glossary of Mineral Species; Lyman, K., ed., 1984, Simon & Schuster’s Guide to Gems and Precious Stones; Mitchell, R.S., 1979, Mineral Names What Do They Mean?; Spencer, L.J., M.H. Hay, et al, various dates, “Annual lists of new mineral names”, Mineralogical Magazine; Chambers Etymological English Dictionary; Encyclopaedia Britannica; Webster’s New Twentieth Century Dictionary (unabridged).