Cotunnite
PbCl2IMA symbol: Cotgrandfathered
Cotunnite is a halide mineral with the formula PbCl2, crystallizing in the orthorhombic system. It has typically white, green or yellow in color, with an adamantine or pearly luster, a specific gravity of 5.238. Its streak is white; cleavage is perfect.
Photos
Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P b n m |
| Cell (Å, °) | a = 9.03, b = 7.608, c = 4.525; α = 90, β = 90, γ = 90 |
| Cell volume | 310.869 ų, Z = 4 |
| Axial ratios | 1.1869:1:0.5948calculated from COD 9009195 |
| Source structure | COD 9009195 (Crystal Structures, 1963) |
Powder X-ray diffraction (calculated)
| d (Å) | 3.572 | 3.883 | 2.771 | 2.506 | 2.093 | 3.804 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 75.7 | 53.9 | 51.1 | 48.2 | 41 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9009195; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 5.942 g/cm³calculated from COD 9009195 |
|---|---|
| Specific gravity | 5.238 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | green, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | adamantine, pearly, silkysingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Cleavage | perfectDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 278.11 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Pb 74.5%, Cl 25.5% |
Classification
| Nickel-Strunz (10th) | 3.DC.85Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 3.DC.85Wikidata (CC0) |