Selenite and satin spar are crystal habit varieties of the mineral gypsum.
All varieties of gypsum, including selenite and Satin Spar are composed of calcium sulfate dehydrate, with the chemical formula CaSO4·2H2O.
The main distinguishing characteristics of crystalline gypsum are their softness (hardness 2 on Mohs scale, soft enough to scratch with a fingernail) and their three unequal cleavages. Other distinguishing characteristics include their crystal habits, pearly luster, easy fusibility with loss of water, and solubility in hot dilute hydrochloric acid.
Selenite
| Properties | Value |
|---|---|
| color | White |
| Crystal System | Monoclinic |
| Transparency | Transparent |
| Tenacity | Brittle |
| Luster | vitreous |
| Mohs hardness | 2 |
| Size | 10mm – 400 mm |
| Specific Gravity(g/cm3) | 2.9 |
Crystal Gypsum
| Properties | Value |
|---|---|
| Chemistry | A variety of Gypsum with the formula CaSO4 · 2H2O. |
| Chemical Classification | Sulfides |
| Colors and Variations | White |
| Luster | Vitreous to silky, pearly, or waxy |
| Streak | White |
| Fracture | Fibrous |
| Transparency | Translucent to opaque |
| Crystal habit | Long fibrous |
| Mohs hardness | 2 |
| Specific Gravity | 2.9 |
| Tenacity | Sectile and brittle. |
Application
- Agriculture
- Food and Drink
- Medicine and Cosmetics
- Modeling, Sculpture and Art
Packing
Bulk in Container and Big Bags in Containers
Chemical Formula
- CaSO4·2H2O
Other names
- Selenite
- satin spar
- desert rose
- gypsum flower