Calcite
| Colour | Clear, White, Orange |
|---|---|
| Mohs hardness | 3 (defining mineral) |
| Lustre | Vitreous to pearly on cleavage surfaces |
| Streak | White |
| Crystal system | Trigonal |
| Transparency | Transparent to translucent |
| Cleavage | Perfect on {101} three directions with angle of 74° 55' |
| Fracture | Conchoidal |
| Chemical formula | CaCO 3 |
| Specific gravity | 2.71 |
What is Calcite?
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scratch hardness comparison. Large calcite crystals are used in optical equipment, and limestone composed mostly of calcite has numerous uses.
How to identify Calcite
- Lustre: Vitreous to pearly on cleavage surfaces.
- Hardness: Mohs 3 (defining mineral) — soft; a knife will scratch it.
- Streak: White.
- Habit: Trigonal crystal system.
Calcite value
Based on 100 recent eBay sold listings, a raw / cluster Calcite typically sells for $7–$23 (about $0.03–$0.08 per gram for raw material). After eBay fees a seller nets roughly $14 on a median piece.
| Recently sold | Weight | Sold | Date |
|---|---|---|---|
| Stunning Cubic Flourite Specimen Combined with Calcite From pakistan 121.54 Gm | — | $18 | 2026-06-22 |
| 1.44LB Natural Rose Petal Calcite Mineral Specimen/Fluorescent Glow Under UV Lig | 653 g | $18 | 2026-06-22 |
| 373G Natural Rose Petal Calcite Mineral Specimen/Fluorescent Glow Under UV Light | 373 g | $13 | 2026-06-22 |
| 154G Natural Amethyst Geode with Calcite Quartz Cluster Crystal Gem Specimen | 154 g | $21 | 2026-06-22 |
| 142G Natural Amethyst Geode with Calcite Quartz Cluster Crystal Gem Specimen | 142 g | $21 | 2026-06-22 |
| 1.33LB Natural Amethyst Geode with Calcite Quartz Cluster Crystal Gem Specimen | 603 g | $17 | 2026-06-22 |
Typical recently-sold prices, 2026-06. Condition, size and quality vary widely, so this is an estimate, not an appraisal. See current sold listings on eBay ↗. Full value guide · how we work this out.
