Nickeline
NiAsIMA symbol: Ncapproved
Nickeline is a sulfide or sulfosalt mineral with the formula NiAs, crystallizing in the hexagonal system. It has a Mohs hardness of 5-5.5, typically black, gray or red in color, with a metallic luster, a specific gravity of 7.33-7.67. Its streak is black or brown.
Photos
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Crystallography
| Crystal system | hexagonal crystal systemWikidata (CC0) |
|---|---|
| Space group | C m c 21 |
| Cell (Å, °) | a = 10.8568, b = 6.2682, c = 5.034; α = 90, β = 90, γ = 90 |
| Cell volume | 342.577 ų, Z = 12 |
| Axial ratios | 1.7320:1:0.8031calculated from COD 9010003 |
| Source structure | COD 9010003 (Journal of Physics C: Solid State Physics, 1988) — 1 of 5 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.661 | 1.962 | 1.809 | 2.661 | 1.962 | 1.809 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 96.2 | 69.6 | 50 | 48 | 35 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9010003; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 7.772 g/cm³calculated from COD 9010003 |
|---|---|
| Hardness (Mohs) | 5-5.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 7.33-7.67 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, gray, redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | black, brownsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 133.62 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ni 43.93%, As 56.07% |
Classification
| Nickel-Strunz (10th) | 2.CC.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 2.CC.05Wikidata (CC0) |
| Dana (8th) | 2.8.11.1Wikidata (CC0) |