Calcite
Ca(CO3)IMA symbol: Calgrandfathered
Calcite is a carbonate or nitrate mineral with the formula Ca(CO3), crystallizing in the trigonal system. It has a Mohs hardness of 3, typically colorless, white, black or blue in color, with an earthy or vitreous luster, a specific gravity of 2.713. Its streak is white or gray.
Photos
Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | R -3 c :H |
| Cell (Å, °) | a = 4.9748, b = 4.9748, c = 17.27; α = 90, β = 90, γ = 120 |
| Cell volume | 370.147 ų, Z = 6 |
| Axial ratios | 1.0000:1:3.4715calculated from COD 9014415 |
| Source structure | COD 9014415 (The Canadian Mineralogist, 2010) — 1 of 43 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.05 | 1.882 | 1.93 | 2.283 | 2.09 | 2.487 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 23.6 | 21.9 | 21.4 | 15.5 | 13.7 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9014415; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.694 g/cm³calculated from COD 9014415 |
|---|---|
| Hardness (Mohs) | 3.04single sourceWikidata (CC0) 3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.713 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, blue, brown, colorless, gray, green, red, violet, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) gray, whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | earthy, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 100.09 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ca 40.04%, C 12%, O 47.96% |
Classification
| Nickel-Strunz (10th) | 5.AB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.AB.05Wikidata (CC0) |
| Dana (8th) | 14.1.1.1Wikidata (CC0) |