Polyhalite | |
Chemical Formula |
K2Ca2MgSO44·2H2O |
Species |
Sulfates |
Crystal System |
Triclinic |
Mohs Scale |
2-3 |
Specific Gravity |
2.78 |
Color |
Colourless, white, pink, red, grey; colourless in transmitted light. |
Luster |
Vitreous, Resinous |
Refractive Index |
n = 1.546 - 1.548 n = 1.558 - 1.562 n = 1.567 |
Diaphaneity |
Transparent |
Cleavage |
Perfect, perfect |
Crystal Habit:Crystals small and rare; tabular or elongated and exhibiting numerous forms. Commonly massive, fibrous to foliated. | |
Geological Setting:Oceanic salt deposits; rarely as a volcanic product. |