Strengite
Iron phosphate mineral
From Wikipedia, the free encyclopedia
Strengite is a relatively rare iron phosphate mineral with the formula: FePO4·2H2O.[5] The mineral is named after the German mineralogist Johann August Streng (1830–1897).[6] Lavender, pink or purple in hue, it is similar to variscite[7] and is partially soluble, particularly in conditions where there is a low pH and low oxidation-reduction potential.[5] The color comes from ferric ion (Fe3+).[8]
| Strengite | |
|---|---|
A small crystal of Strengite | |
| General | |
| Category | Minerals |
| Formula | FePO4·2H2O |
| IMA symbol | Stg[1] |
| Strunz classification | 8.CD.10 |
| Dana classification | 40.04.01.02 |
| Crystal system | Orthorhombic |
| Crystal class | Dipyramidal (mmm) H-M Symbol: (2/m 2/m 2/m) |
| Space group | Pcab |
| Identification | |
| Formula mass | 186.85 g/mol |
| Color | Colorless, pale violet, deep violet, red, carmine red, greenish white |
| Crystal habit | Botryoidal, radial, spherical |
| Cleavage | {010} Good, {001} Poor |
| Mohs scale hardness | 3.5–4 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 2.84 |
| Density | 2.87 g/cm3 |
| Optical properties | Biaxial (+) |
| 2V angle | 72° – 88° |
| Dispersion | r < v, relatively strong |
| References | [2][3][4] |
