Villiaumite
NaFIMA symbol: Vllgrandfathered
Villiaumite is a halide mineral with the formula NaF, crystallizing in the cubic system. It has a Mohs hardness of 2-2.25, typically red in color, a specific gravity of 2.79. Its streak is white.
Photos
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Crystallography
| Crystal system | cubic crystal systemWikidata (CC0) |
|---|---|
| Space group | F m -3 m |
| Cell (Å, °) | a = 4.62, b = 4.62, c = 4.62; α = 90, β = 90, γ = 90 |
| Cell volume | 98.611 ų, Z = 4 |
| Axial ratios | 1.0000:1:1.0000calculated from COD 9008679 |
| Source structure | COD 9008679 (Crystal Structures, 1963) — 1 of 10 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.31 | 1.633 | 1.334 | 1.155 | 2.667 | 1.393 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 57.5 | 16.6 | 6.8 | 2.2 | 1.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9008679; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.828 g/cm³calculated from COD 9008679 |
|---|---|
| Hardness (Mohs) | 2-2.25single sourceDana's System, 2nd Appendix (1909) |
| Specific gravity | 2.79 g/cm3corroboratedDana's System, 2nd Appendix (1909) |
| Color | redDana's System, 2nd Appendix (1909) |
| Streak | whitesingle sourceWikidata (CC0) |
Chemistry (calculated)
| Molecular weight | 41.99 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Na 54.75%, F 45.25% |
Classification
| Nickel-Strunz (10th) | 3.AA.20Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 3.AA.20Wikidata (CC0) |