Austinite
Arsenate mineral / From Wikipedia, the free encyclopedia
Not to be confused with Austenite.
This article is about the mineral. For people from the city, see List of people from Austin, Texas.
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.
Quick Facts General, Category ...
Austinite | |
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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] |
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