Pyromorphite
Pb5(PO4)3ClIMA symbol: Pymgrandfathered
Pyromorphite is a phosphate, arsenate, or vanadate mineral with the formula Pb5(PO4)3Cl. It has a Mohs hardness of 3.5-4, typically white, brown, gray or green in color, with a resinous luster, a specific gravity of 5.89-6.44. Its streak is white or yellow.
Photos
Crystallography
| Space group | P 63/m |
|---|---|
| Cell (Å, °) | a = 9.986, b = 9.986, c = 7.3378; α = 90, β = 90, γ = 120 |
| Cell volume | 633.694 ų, Z = 2 |
| Axial ratios | 1.0000:1:0.7348calculated from COD 9016947 |
| Source structure | COD 9016947 (American Mineralogist, 2013) — 1 of 9 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.957 | 2.986 | 2.883 | 4.128 | 2.064 | 3.269 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 92.8 | 54.1 | 42.6 | 39.1 | 34.7 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9016947; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 6.757 g/cm³calculated from COD 9016947 |
|---|---|
| Hardness (Mohs) | 3.5-4single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 5.89-6.44 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, gray, green, orange, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | resinoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 1356.37 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Pb 76.38%, P 6.85%, O 14.15%, Cl 2.61% |
Classification
| Nickel-Strunz (10th) | 8.BN.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 8.BN.05Wikidata (CC0) |