| Chemical formula | CaSO4 |
| Class | Sulfate (anhydrous) |
| Crystal system | Orthorhombic |
| Habit | Massive Granular Fibrous Tabular (rare) Prismatic (rare) |
| Color | Colorless Blueish Violet Reddish Brownish Gray |
| Hardness | 3 – 3.5 |
| Specific gravity | 2.98 |
| Cleavage/fracture | Perfect cubic (010) Good (100) and (001) Uneven Splintery |
| Luster | Vitreous Pearly |
| Transparency | Translucent to transparent |
| Streak | White |
| δ | .044 |
| PPL | Colorless Pseudocubic cleavage |
| XPL | Up to 3rd order greens |
| Extinction | Parallel |
| after Perkins, 392 |
Anhydrite in hand sample
Anhydrite
Greyish anhydrite alternating with brownish organic-rich calcite
Anhydrite in thin section
Stay tuned for explorable images
