Calcite
Calcite is known for its strong cleavage (tendency to break easily) and unique optical properties, making it useful for Nicol prisms and optical materials.
It is also recognized as a building block for fossils and stalactites, and comes in a rich variety of colors and shapes.
Translucent Calcite
Basic Information
| Chemical Formula | CaCO₃ |
|---|---|
| Classification | Hexagonal (Trigonal) |
| Hardness | 3 (Mohs hardness) |
| Specific Gravity | Approx. 2.71 |
| Crystal Form | Cleavable, massive |
Features
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Birefringence: Calcite exhibits very strong birefringence, a property that causes images to appear doubled when viewed through the crystal.
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Spar: A classification term used for non-metallic, lustrous minerals, of which calcite is a prime example.
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Color Variations: Colorless Pink Yellowish-white
Varieties & Alternate Names
- Variety Stalactite / Stalagmite: Calcite deposited within caves.
- Variety Cobalt calcite / Manganese calcite: Colored by trace elements.
- Alternate Name Iceland spar: Also used for optical applications.
Note: Handle with care as it is sensitive to impact.