Gwihabaite | |
---|---|
General | |
Category | Mineral |
Formula (repeating unit) | (NH4,K)NO3 |
IMA symbol | Gwi [1] |
Strunz classification | 5.NA.15 |
Dana classification | 18.01.03.01 |
Crystal system | Orthorhombic |
Crystal class | Dipyramidal |
Space group | Pmna (No. 62) |
Unit cell | a=7.075Å, b=7.647Å, c=5.779Å, Z=4 |
Identification | |
Formula mass | 85.31 |
Colour | White, colourless |
Crystal habit | Acicular, Efflorescences |
Cleavage | None |
Mohs scale hardness | 5 |
Luster | Vitreous |
Streak | White |
Diaphaneity | Transparent |
Density | 1.77 |
Birefringence | 0.141 |
2V angle | 87◦ |
Dispersion | None |
Solubility | Soluble in H2O , deliquescent |
Gwihabaite is a rare ammonium potassium nitrate mineral (NH4,K)(NO3). It is orthorhombic in form, colorless with a vitreous luster. It has a Mohs hardness of 5 and a specific gravity of 1.77. It is deliquescent and water-soluble. The mineral is also known as nitrammite. It was first described in 1996 for an occurrence in Gcwihaba Caves (Drotsky's Cavern, type locality), Maun, North-West District, Botswana. The spelling of the name was simplified, omitting the "c", which represents the "click" sound used by the San people. It occurs as incrustations and efflorescences on cave surfaces formed by bacterial action on bat guano. [2] [3]
Celestine (the IMA-accepted name) or celestite is a mineral consisting of strontium sulfate (SrSO4). The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys.
Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, CaCO3. It is formed by biological and physical processes, including precipitation from marine and freshwater environments.
Hemimorphite is the chemical compound Zn4(Si2O7)(OH)2·H2O, a component of mineral calamine. It is a silicate mineral which, together with smithsonite (ZnCO3), has been historically mined from the upper parts of zinc and lead ores. Both compounds were originally believed to be the same mineral and classified as calamine. In the second half of the 18th century, it was discovered that these two different compounds were both present in calamine. They closely resemble one another.
Niter or nitre is the mineral form of potassium nitrate, KNO3. It is a soft, white, highly soluble mineral found primarily in arid climates or cave deposits.
Chalcocite, copper(I) sulfide (Cu2S), is an important copper ore mineral. It is opaque and dark gray to black, with a metallic luster. It has a hardness of 2.5–3 on the Mohs scale. It is a sulfide with a monoclinic crystal system.
Pyrolusite is a mineral consisting essentially of manganese dioxide (MnO2) and is important as an ore of manganese. It is a black, amorphous appearing mineral, often with a granular, fibrous, or columnar structure, sometimes forming reniform crusts. It has a metallic luster, a black or bluish-black streak, and readily soils the fingers. The specific gravity is about 4.8. Its name is from the Greek for fire and to wash, in reference to its use as a way to remove tints from glass.
Thénardite is an anhydrous sodium sulfate mineral, Na2SO4 which occurs in arid evaporite environments, specifically lakes and playas. It also occurs in dry caves and old mine workings as an efflorescence and as a crusty sublimate deposit around fumaroles. It occurs in volcanic caves on Mount Etna, Italy. It was first described in 1825 for an occurrence in the Espartinas Saltworks, Ciempozuelos, Madrid, Spain and was named for the French chemist, Louis Jacques Thénard (1777–1826).
Diadochite is a phospho-sulfate mineral. It is a secondary mineral formed by the weathering and hydration of other minerals. Its formula is Fe2(PO4)(SO4)OH·5H2O. Well crystallized forms are referred to as destinezite, which has been given official recognition by the International Mineralogical Association with diadochite being the poorly formed to amorphous variety.
Aluminite is a hydrous aluminium sulfate mineral with formula: Al2SO4(OH)4·7H2O. It is an earthy white to gray-white monoclinic mineral which almost never exhibits crystal form. It forms botryoidal to mammillary clay-like masses. It has a very soft Mohs hardness of 1–2 and a specific gravity of 1.66–1.82.
Copiapite is a hydrated iron sulfate mineral with formula: Fe2+Fe3+4(SO4)6(OH)2·20(H2O). Copiapite can also refer to a mineral group, the copiapite group.
Brushite is a phosphate mineral with the chemical formula CaHPO4·2H2O. Crystals of the pure compound belong to the monoclinic space group C2/c and are colorless. It is the phosphate analogue of the arsenate pharmacolite.
Zabuyelite is the natural mineral form of lithium carbonate, with a formula Li2CO3. It was discovered in 1987 at Lake Zabuye, Tibet, after which it is named. It forms colorless vitreous monoclinic crystals.
Uricite is a rare organic mineral form of uric acid, C5H4N4O3. It is a soft yellowish white mineral which crystallizes in the monoclinic system.
Taranakite is a hydrated alkali iron-aluminium phosphate mineral with chemical formula (K,Na)3(Al,Fe3+)5(PO4)2(HPO4)6·18 H2O. It forms from the reaction of clay minerals or aluminous rocks with solutions enriched in phosphate derived from bat or bird guano or, less commonly, from bones or other organic matter. Taranakite is most commonly found in humid, bat inhabited caves near the boundary of guano layers with the cave surface. It is also found in perennially wet coastal locations that have been occupied by bird colonies. The type location, and its namesake, the Sugar Loaf Islands off Taranaki, New Zealand, is an example of a coastal occurrence.
Woodhouseite belongs to the beudantite group AB3(XO4)(SO4)(OH)6 where A = Ba, Ca, Pb or Sr, B = Al or Fe and X = S, As or P. Minerals in this group are isostructural with each other and also with minerals in the crandallite and alunite groups. They crystallise in the rhombohedral system with space group R3m and crystals are usually either tabular {0001} or pseudo-cubic to pseudo-cuboctahedral. Woodhouseite was named after Professor Charles Douglas Woodhouse (1888–1975), an American mineralogist and mineral collector from the University of California, Santa Barbara, US, and one-time General Manager of Champion Sillimanite, Inc.
Alum-(K) is a hydrous potassium aluminium sulfate mineral with formula KAl(SO4)2·12(H2O). It is the mineral form of potassium alum and is referred to as potassium alum in older sources. It is a member of the alum group.
Bassanite is a calcium sulfate mineral with formula CaSO4·1/2H2O or 2CaSO4·H2O. In other words it has half a water molecule per CaSO4 unit, hence its synonym calcium sulfate hemihydrate.
Syngenite is an uncommon potassium calcium sulfate mineral with formula K2Ca(SO4)2·H2O. It forms as prismatic monoclinic crystals and as encrustations.
Pickeringite is a magnesium aluminium sulfate mineral with formula MgAl2(SO4)4·22(H2O). It forms a series with halotrichite.