Calcite vs Fluorite
| Property | Calcite | Fluorite |
|---|---|---|
| 化学式 | CaCO3 | CaF2 |
| 晶系 | Trigonal | Cubic (Isometric) |
| 鉱物分類 | 05 Carbonates and Nitrates | 03 Halides |
| モース硬度 | 3.0 | 4.0 |
| 色 | Colorless, white, yellow, orange, blue, green | Purple, blue, green, yellow, colorless, pink |
| 光沢 | Vitreous | Vitreous |
| 条痕色 | White | White |
| 透明度 | Transparent | Transparent |
| 劈開 | Perfect rhombohedral {1011} | Perfect octahedral {111} |
| 断口 | Conchoidal | Conchoidal |
Key Differences
- ◆ Calcite (hardness 3) is scratched by a copper coin; fluorite (hardness 4) requires a steel knife to scratch.
- ◆ Calcite reacts vigorously with dilute HCl; fluorite does not react with HCl.
- ◆ Fluorite has perfect octahedral cleavage (4 directions); calcite has perfect rhombohedral cleavage (3 directions).
- ◆ Fluorite (CaF2) is a halide; calcite (CaCO3) is a carbonate.
- ◆ Fluorite fluoresces under UV light (phenomenon named after it); calcite rarely fluoresces.