Borax | |
---|---|
General | |
Category | Nesoborate |
Formula (repeating unit) | Na2B4O5(OH)4·8H2O |
IMA symbol | Brx [1] |
Strunz classification | 6.DA.10 |
Crystal system | Monoclinic |
Crystal class | Prismatic (2/m) (same H-M symbol) |
Space group | C2/c (no. 15) |
Unit cell | a = 11.8790(2) Å, b = 10.6440(2) Å, c = 12.2012(2) Å; β = 106.617(1)°; Z = 4 |
Identification | |
Color | Colorless or white |
Crystal habit | As prismatic crystals or as massive encrustations |
Twinning | Rare on {100} |
Cleavage | Perfect on {100}, less perfect on {100}, very poor on {010} |
Fracture | Conchoidal |
Mohs scale hardness | 2 to 2.5 |
Luster | Vitreous to resinous to earthy |
Streak | White |
Diaphaneity | Translucent to opaque |
Specific gravity | 1.715 |
Optical properties | Biaxial (-) |
Refractive index | nα = 1.4466 nβ = 1.4687 nγ = 1.4717 |
Fusibility | 1.5 |
Diagnostic features | Froths on heating, producing a yellow flame |
Solubility | Soluble in water |
References | [2] [3] [4] [5] |
Borax (Na2B4O5(OH)4·8 H2O [2] ) is a borate mineral found in evaporite deposits of alkaline lacustrine environments and as a surface efflorescence in arid regions. It is the chief mineral mined from the deposits at Boron, California and nearby locations, and is the chief source of commercial borax. [5]
Borax first reached Western civilization as tincal mined from deposits in Tibet. [5] The term borax comes from the Arabic bauraq, meaning white. [3]
The most extensive deposits are in Kirka, Turkey. Borax is also mined in the Andes Mountains of Argentina, Bolivia, and Chile. However, the greatest production is from the deposits in California. [5]
Natural occurrences of the mineral are an important source of commercial borax, which is used for the manufacture of glass fibers, in cleaning agents, as an antiseptic, and as a flux in metallurgy and solvent for metal oxides. [5]
Amblygonite is a fluorophosphate mineral, (Li,Na)AlPO4(F,OH), composed of lithium, sodium, aluminium, phosphate, fluoride and hydroxide. The mineral occurs in pegmatite deposits and is easily mistaken for albite and other feldspars. Its density, cleavage and flame test for lithium are diagnostic. Amblygonite forms a series with montebrasite, the low fluorine endmember. Geologic occurrence is in granite pegmatites, high-temperature tin veins, and greisens. Amblygonite occurs with spodumene, apatite, lepidolite, tourmaline, and other lithium-bearing minerals in pegmatite veins. It contains about 10% lithium, and has been utilized as a source of lithium. The chief commercial sources have historically been the deposits of California and France.
Kernite, also known as rasorite, is a hydrated sodium borate hydroxide mineral with formula Na
2B
4O
6(OH)
2·3H
2O. It is a colorless to white mineral crystallizing in the monoclinic crystal system typically occurring as prismatic to acicular crystals or granular masses. It is relatively soft with Mohs hardness of 2.5 to 3 and light with a specific gravity of 1.91. It exhibits perfect cleavage and a brittle fracture.
Uraninite, also known as pitchblende, is a radioactive, uranium-rich mineral and ore with a chemical composition that is largely UO2 but because of oxidation typically contains variable proportions of U3O8. Radioactive decay of the uranium causes the mineral to contain oxides of lead and trace amounts of helium. It may also contain thorium and rare-earth elements.
Cinnabar, or cinnabarite, also known as mercurblende is the bright scarlet to brick-red form of mercury(II) sulfide (HgS). It is the most common source ore for refining elemental mercury and is the historic source for the brilliant red or scarlet pigment termed vermilion and associated red mercury pigments.
Turquoise is an opaque, blue-to-green mineral that is a hydrous phosphate of copper and aluminium, with the chemical formula CuAl6(PO4)4(OH)8·4H2O. It is rare and valuable in finer grades and has been prized as a gemstone for millennia due to its hue.
Spodumene is a pyroxene mineral consisting of lithium aluminium inosilicate, LiAl(SiO3)2, and is a commercially important source of lithium. It occurs as colorless to yellowish, purplish, or lilac kunzite (see below), yellowish-green or emerald-green hiddenite, prismatic crystals, often of great size. Single crystals of 14.3 m (47 ft) in size are reported from the Black Hills of South Dakota, United States.
Cassiterite is a tin oxide mineral, SnO2. It is generally opaque, but it is translucent in thin crystals. Its luster and multiple crystal faces produce a desirable gem. Cassiterite was the chief tin ore throughout ancient history and remains the most important source of tin today.
Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver.
Nickeline or niccolite is the mineral form of nickel arsenide. The naturally-occurring mineral contains roughly 43.9% nickel and 56.1% arsenic by mass, but composition of the mineral may vary slightly.
Colemanite (Ca2B6O11·5H2O) or (CaB3O4(OH)3·H2O) is a borate mineral found in evaporite deposits of alkaline lacustrine environments. Colemanite is a secondary mineral that forms by alteration of borax and ulexite.
Mimetite is a lead arsenate chloride mineral (Pb5(AsO4)3Cl) which forms as a secondary mineral in lead deposits, usually by the oxidation of galena and arsenopyrite. The name derives from the Greek Μιμητής mimetes, meaning "imitator" and refers to mimetite's resemblance to the mineral pyromorphite. This resemblance is not coincidental, as mimetite forms a mineral series with pyromorphite (Pb5(PO4)3Cl) and with vanadinite (Pb5(VO4)3Cl). Notable occurrences are Mapimi, Durango, Mexico and Tsumeb, Namibia.
Native copper is an uncombined form of copper that occurs as a natural mineral. Copper is one of the few metallic elements to occur in native form, although it most commonly occurs in oxidized states and mixed with other elements. Native copper was an important ore of copper in historic times and was used by pre-historic peoples.
Francis Marion Smith was an American miner, business magnate and civic builder in the Mojave Desert, the San Francisco Bay Area, and Oakland, California. He was known nationally and internationally as "Borax Smith" and "The Borax King", as his company produced the popular 20-Mule-Team Borax brand of household cleaner.
Hanksite is a sulfate mineral, distinguished as one of only a handful that contain both carbonate and sulfate ions (a sulfate carbonate). It has the chemical formula Na22K(SO4)9(CO3)2Cl.
Nitratine or nitratite, also known as cubic niter (UK: nitre), soda niter or Chile saltpeter (UK: Chile saltpetre), is a mineral, the naturally occurring form of sodium nitrate, NaNO3. Chemically it is the sodium analogue of saltpeter. Nitratine crystallizes in the trigonal system, but rarely occurs as well-formed crystals. It is isostructural with calcite. It is relatively soft and light with a Mohs hardness of 1.5 to 2 and a specific gravity of 2.24 to 2.29. Its refractive indices are nω = 1.587 and nε = 1.336.
Hectorite is a rare soft, greasy, white clay mineral with a chemical formula of Na0.3(Mg,Li)3Si4O10(OH)2.
Nahcolite is a soft, colourless or white carbonate mineral with the composition of sodium bicarbonate (NaHCO3) also called thermokalite. It crystallizes in the monoclinic system.
The Rio Tinto Boron Mine in Boron, California is California's largest open-pit mine and the largest borax mine in the world, producing nearly half the world's borates. Ore reserves are sufficient for current economic production through early 2040's. It is operated by the Borax division of the Rio Tinto Group.
Pinnoite is a magnesium borate mineral with formula: MgB2O(OH)6 or MgB2O4·3(H2O). It crystallizes in the tetragonal crystal system and occurs as colorless to yellow or light green radial fibrous clusters and rarely as short prismatic crystals.
The Potash wars were a series of events that took place from 1910 to 1915 in the Searles Valley near Searles Lake, a dry lake, near the current town of Trona in the San Bernardino County of California. The Potash wars gained national and international news at the time due to the involvement of famous lawman Wyatt Earp and the importance of the valley's supply of potash at the time. Potash is an important crop fertilizer and the Searles Valley was a major supplier in the 1910s.