Iceland spar
Varietyof Calcite
Iceland spar is optically clear calcite. As a variety of Calcite, it shares that species' composition (Ca(CO3)), crystal structure, and hardness; the distinction is the appearance defined above.
Photos
About Calcite
Full reference data — crystallography, X-ray diffraction, and cited physical properties — is on the Calcite species page.
| Formula | Ca(CO3) |
|---|---|
| Hardness (Mohs) | 3 |
| Specific gravity | 2.713 |
| Density (calculated) | 2.694 |
| Crystal system | trigonal |
| Color range | black, blue, brown, colorless, gray, green, red, violet, white, yellow |
| Luster | earthy, vitreous |
| Streak | gray, white |