Brochantite
Cu4(SO4)(OH)6IMA symbol: Bctapproved
Brochantite is a sulfate mineral with the formula Cu4(SO4)(OH)6, crystallizing in the monoclinic system. It has a Mohs hardness of 3.5-4, typically black or green in color, with a pearly or vitreous luster, a specific gravity of 3.907. Its streak is green.
Photos
Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/a 1 |
| Cell (Å, °) | a = 13.1117, b = 9.8654, c = 6.0307; α = 90, β = 103.255, γ = 90 |
| Cell volume | 759.302 ų, Z = 4 |
| Axial ratios | 1.3291:1:0.6113calculated from COD 9016521 |
| Source structure | COD 9016521 (European Journal of Mineralogy, 2010) — 1 of 3 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.903 | 5.358 | 6.381 | 2.679 | 2.522 | 2.522 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 90.5 | 87.5 | 86.5 | 86.2 | 85.8 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9016521; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.904 g/cm³calculated from COD 9016521 |
|---|---|
| Hardness (Mohs) | 3.5-4single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3.907 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, greensingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | greensingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | pearly, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 452.29 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Cu 56.2%, S 7.09%, O 35.37%, H 1.34% |
Classification
| Nickel-Strunz (10th) | 7.BB.25Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.BB.25Wikidata (CC0) |
| Dana (8th) | 30.1.3.1Wikidata (CC0) |