Fornacite
CuPb2(CrO4)(AsO4)(OH)IMA symbol: Forgrandfathered
Fornacite is a sulfate mineral with the formula CuPb2(CrO4)(AsO4)(OH), crystallizing in the monoclinic system. It has a Mohs hardness of 2.5, a calculated density of 6.254 g/cm3. Its streak is olive.
Photos
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Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/c 1 |
| Cell (Å, °) | a = 8.09015, b = 5.90913, c = 17.4839; α = 90, β = 109.99, γ = 90 |
| Cell volume | 785.474 ų, Z = 4 |
| Axial ratios | 1.3691:1:2.9588calculated from COD 9017463 |
| Source structure | COD 9017463 (Doklady Earth Sciences, 2014) — 1 of 2 structures |
Physical properties
| Density (calculated) | 6.254 g/cm³calculated from COD 9017463 |
|---|---|
| Hardness (Mohs) | 2.5single sourceWikidata (CC0) |
| Streak | olivesingle sourceWikidata (CC0) |
Chemistry (calculated)
| Molecular weight | 749.87 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Cu 8.47%, Pb 55.26%, Cr 6.93%, O 19.2%, As 9.99%, H 0.13% |
Classification
| Nickel-Strunz (10th) | 7.FC.10Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 7.FC.10Wikidata (CC0) |
| Dana (8th) | 43.4.3.2Wikidata (CC0) |