| Boussingaultite | |
|---|---|
| General | |
| Category | Sulfate mineral |
| Formula (repeating unit) | (NH4)2Mg(SO4)2·6H2O |
| IMA symbol | Bsg[1] |
| Strunz classification | 7.CC.60 |
| Dana classification | 29.03.07.02 |
| Crystal system | Monoclinic |
| Crystal class | Prismatic (2/m) (same H-M symbol) |
| Space group | P21/a |
| Unit cell | a = 9.324(7) Å, b = 12.597(9) Å, c = 6.211(5) Å; β = 1.472°; Z = 2 |
| Identification | |
| Formula mass | 360.60 g/mol |
| Color | Colorless, yellow pink, light yellow, pink; colorless in transmitted light |
| Cleavage | {201} perfect (synthetic) |
| Mohs scale hardness | 2 |
| Luster | Vitreous (glassy), silky |
| Streak | White |
| Diaphaneity | Transparent to translucent |
| Specific gravity | 1.73 |
| Density | 1.7 g/cm3 |
| Optical properties | Biaxial (+) |
| 2V angle | 51°11′ |
| Dispersion | r > v, perceptible |
| Solubility | Soluble in H2O |
| References | [2][3][4] |
Boussingaultite is a rare ammonium magnesium hydrated sulfate mineral of the chemical formula: (NH4)2Mg(SO4)2 · 6 H2O. The formula of boussingaultite is that of Tutton's salts type. It was originally described from geothermal fields in Tuscany, Italy, where it occurs together with its iron analogue mohrite,[5] but is more commonly found on burning coal dumps.[6] The mineral possess monoclinic symmetry and forms clear, often rounded crystals.[3]
The mineral is named after the French chemist Jean-Baptiste Boussingault (1802–1887).[7]