Cinnabar
HgSIMA symbol: Cingrandfathered
Cinnabar is a sulfide or sulfosalt mineral with the formula HgS, crystallizing in the trigonal system. It has a Mohs hardness of 2-2.5, typically red in color, with an adamantine or dull luster, a specific gravity of 8-8.2. Its streak is red; cleavage is perfect.
Photos
Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | P 32 2 1 |
| Cell (Å, °) | a = 4.145, b = 4.145, c = 9.496; α = 90, β = 90, γ = 120 |
| Cell volume | 141.293 ų, Z = 3 |
| Axial ratios | 1.0000:1:2.2910calculated from COD 9012082 |
| Source structure | COD 9012082 (Bulletin de la Societe Francaise de Mineralogie et de Cristallographie, 1973) — 1 of 3 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.358 | 2.863 | 1.98 | 1.734 | 2.072 | 3.165 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 93.5 | 32.7 | 29.8 | 27.3 | 24.1 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9012082; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 8.203 g/cm³calculated from COD 9012082 |
|---|---|
| Hardness (Mohs) | 2.3single sourceWikidata (CC0) 2-2.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 8-8.2 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | redDana, System of Mineralogy, 6th ed. (1892) |
| Luster | adamantine, dull, metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Cleavage | perfectDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 232.66 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Hg 86.22%, S 13.78% |
Classification
| Nickel-Strunz (10th) | 2.CD.15aWikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 2.CD.15aWikidata (CC0) |
| Dana (8th) | 2.8.14.1Wikidata (CC0) |