| Augelite | |
|---|---|
 | |
| General | |
| Category | Phosphate mineral |
| Formula | Al2(PO4)(OH)3 |
| IMA symbol | Aul[1] |
| Strunz classification | 8.BE.05 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (sameH-M symbol) |
| Space group | C2/m |
| Unit cell | a = 13.124(6), b = 7.988(5) c = 5.0633(3) [Å] β = 112.25(2)°; Z = 4 |
| Identification | |
| Color | Colorless to white, may be yellowish to pale rose, greenish |
| Crystal habit | Tabular to prismatic or acicular crystals; massive |
| Cleavage | Perfect on {110}, good on {201}, imperfect on {001} and {101} |
| Fracture | Uneven |
| Tenacity | Brittle |
| Mohs scale hardness | 4 – 4.5 |
| Luster | Vitreous, pearly on {110} cleavage |
| Streak | White |
| Diaphaneity | Transparent |
| Specific gravity | 2.696 |
| Optical properties | Biaxial (+) |
| Refractive index | nα = 1.574 nβ = 1.576 nγ = 1.588 |
| Birefringence | δ = 0.014 |
| 2V angle | Measured: 50° |
| References | [2][3] |
Augelite is an aluminiumphosphate mineral with formula:Al2(PO4)(OH)3. The shade varies from colorless to white, yellow or rose. Itscrystal system ismonoclinic.[4]
It was first described byChristian Wilhelm Blomstrand for an occurrence inVästanå iron mine atScania,Sweden in 1868 and derives its name from theGreek αύγή in reference to its pearlylustre.[2][3]
It occurs as a product ofmetamorphism ofphosphate bearing peraluminous sediments and in high-temperaturehydrothermalore deposits. It occurs in association withattakolite,svanbergite,lazulite,hematite,trolleite,berlinite,rutile,pyrophyllite,baryte,arsenopyrite,stannite,pyrite,andorite,cassiterite andzinkenite.[2]
 | This article about a specificphosphate mineral is astub. You can help Wikipedia byexpanding it. |