Löllingite
FeAs2IMA symbol: Lögrandfathered
Löllingite is a sulfide or sulfosalt mineral with the formula FeAs2, crystallizing in the orthorhombic system. It has a Mohs hardness of 5-5.5, typically white, black or gray in color, with a metallic luster, a specific gravity of 7-7.4. Its streak is black or gray.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P n n m |
| Cell (Å, °) | a = 5.243, b = 5.978, c = 2.9783; α = 90, β = 90, γ = 90 |
| Cell volume | 93.348 ų, Z = 2 |
| Axial ratios | 0.8770:1:0.4982calculated from COD 9009410 |
| Source structure | COD 9009410 (Neues Jahrbuch fur Mineralogie, Monatshefte, 2001) — 1 of 9 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.597 | 2.376 | 2.59 | 1.869 | 1.656 | 1.644 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 88.1 | 83.6 | 60.3 | 45.2 | 35.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9009410; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 7.394 g/cm³calculated from COD 9009410 |
|---|---|
| Hardness (Mohs) | 5-5.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 7-7.4 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, gray, whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | black, graysingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 205.69 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Fe 27.15%, As 72.85% |
Classification
| Nickel-Strunz (10th) | 2.EB.15aWikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 2.EB.15aWikidata (CC0) |
| Dana (8th) | 2.12.2.9Wikidata (CC0) |