Gottlobite
| Gottlobite | |
|---|---|
| General | |
| Category | Hydroxide mineral, Vanadate mineral |
| Formula | CaMg(VO4)(OH) |
| IMA symbol | Got |
| Strunz classification | 08.BH.35 |
| Dana classification | 41.05.01.10 |
| Crystal system | Orthorhombic |
| Space group | P222 |
| Unit cell | a = 7.501(4) Å; b = 9.010(7) Å; c = 5.941(4) Å; Z = 4, V = 401.5Å3 |
| Identification | |
| Formula mass | 205.20 gm |
| Color | Orange to orange-brown |
| Crystal habit | Isometric to tabular crystals |
| Twinning | Not observed |
| Cleavage | Not observed |
| Fracture | Conchoidal to irregular |
| Tenacity | Brittle |
| Mohs scale hardness | 4.5 |
| Luster | Vitreous to adamantine |
| Streak | Light brownish |
| Diaphaneity | Transparent |
| Specific gravity | 3.46 g/cm3 (calculated) |
| Optical properties | Biaxial negative |
| Refractive index | nα = 1.797 nβ = 1.805-1.815 nγ = 1.828 |
| Pleochroism | Medium strong with X = orange-brown, Y = pale yellowish brown, and Z = orange-brown |
| Group | Vandates and arsenates |
| References | |
Gottlobite, CaMg(VO4,AsO4)(OH), is a mineral in the adelite group found as isolated crystals or isometric grains of orange or orange-brown color. The size of the crystals are a half millimeter in diameter and are part of the orthorhombic crystal system. Gottlobite is the vanadate end member in a solid solution formed with adelite (CaMg(AsO4)(OH)). Gottlobite is also part of the vanadates and arsenates group. With these characteristics, it is similar to the minerals tangeite and austinite by X-ray diffraction methods.