| Austinite | |
|---|---|
 Austinite from the Ojuela Mine, Mexico | |
| General | |
| Category | Arsenate minerals |
| Formula (repeating unit) | CaZnAsO4(OH) |
| IMA symbol | Aus[1] |
| Strunz classification | 8.BH.35 |
| Dana classification | 41.5.1.3 |
| Crystal system | Orthorhombic |
| Crystal class | Disphenoidal (222) H-M symbol: (2 2 2) |
| Space group | P212121[2] |
| Unit cell | a = 7.43, b = 9.00 c = 5.90 [Å], Z = 4[3] |
| Identification | |
| Formula mass | 261.38 g/mol |
| Color | Colourless, white to pale yellowish-white or bright green, colourless in transmitted light[4] |
| Crystal habit | Well developed orthorhombic crystals of bladed or acicular habit elongated parallel to the c axis, sometimes with sceptre-like terminations, also radially fibrous crusts and nodules. Common forms are {110}, {111}, {1–11}, {010} and {011}.[2] |
| Twinning | Left- and right-handed individuals joined on {100}, with {010} and {001} coincident.[5] |
| Cleavage | Good in two directions parallel to the prism faces {110}[2] |
| Tenacity | Brittle |
| Mohs scale hardness | 4 to 4.5 |
| Luster | Subadamantine to silky in fibrous aggregates |
| Streak | White |
| Diaphaneity | Translucent to transparent |
| Specific gravity | 4.12 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.759, nβ = 1.763, nγ = 1.783, |
| Birefringence | 0.024[2] |
| 2V angle | 47°[2] |
| Dispersion | r > v weak |
| Solubility | Easily soluble in cold dilute HCl[2] |
| Other characteristics | Non-radioactive. Some austinite fluoresces green under SWUV. |
| References | [4][6] |
Austinite is a member of the adelite-descloizite group, adelite subgroup, the zinc (Zn) end member of the copper-Zn series with conichalcite. It is the zinc analogue of cobaltaustinite and nickelaustinite.[4] At one time “brickerite” was thought to be a different species, but it is now considered to be identical to austinite.[7] Austinite is named in honour of Austin Flint Rogers (1877–1957), American mineralogist from Stanford University, California, US.
- ^ Warr, L.N. (2021). "IMA–CNMNC approved mineral symbols". Mineralogical Magazine. 85 (3): 291–320. Bibcode:2021MinM...85..291W. doi:10.1180/mgm.2021.43. S2CID 235729616.
- ^ a b c d e f L. W. Staples (1935). "Austinite, a new arsenate mineral, from Gold Hill, Utah" (PDF). American Mineralogist. 20: 112–119.
- ^ Wallace E. Richmond (1940). "Crystal chemistry of the phosphates, arsenates and vanadates of the type A2XO4(Z)" (PDF). American Mineralogist. 25: 441.
- ^ a b c Austinite: Austinite mineral information and data. Mindat.org. Retrieved on 2011-10-09.
- ^ Sidney A. Williams and Julie de Azevedo (1967). "Austinite from Gold Hill, Utah" (PDF). American Mineralogist. 52: 1224–1226.
- ^ Austinite Mineral Data. Webmineral.com. Retrieved on 2011-10-09.
- ^ Wolfgang Brendler (1938). "On the identity of austinite and brickerite" (PDF). American Mineralogist. 23: 347.