Népouite
Ni3Si2O5(OH)4IMA symbol: Npograndfathered
Népouite is a silicate mineral with the formula Ni3Si2O5(OH)4, crystallizing in the orthorhombic system. It has a Mohs hardness of 2-2.5, typically green in color, with a pearly luster, a specific gravity of 2.47-3.24. Cleavage is imperfect or perfect.
Photos
Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | C 1 m 1 |
| Cell (Å, °) | a = 5.29, b = 9.17, c = 7.26; α = 90, β = 90, γ = 90 |
| Cell volume | 352 ų, Z = 2 |
| Axial ratios | 0.5769:1:0.7917calculated from COD 1548974 |
| Source structure | COD 1548974 (American Mineralogist, 1975) |
Powder X-ray diffraction (calculated)
| d (Å) | 7.26 | 2.487 | 2.139 | 3.63 | 2.485 | 3.875 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 33.3 | 21.3 | 18.3 | 14.5 | 10.7 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 1548974; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.47 g/cm³calculated from COD 1548974 |
|---|---|
| Hardness (Mohs) | 2-2.5Dana's System, 2nd Appendix (1909) |
| Specific gravity | 2.47-3.24 g/cm3Dana's System, 2nd Appendix (1909) |
| Color | greenDana's System, 2nd Appendix (1909) |
| Luster | pearlyDana's System, 2nd Appendix (1909) |
| Cleavage | imperfect, perfectDana's System, 2nd Appendix (1909) |
Chemistry (calculated)
| Molecular weight | 380.28 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ni 46.3%, Si 14.77%, O 37.87%, H 1.06% |
Classification
| Nickel-Strunz (10th) | 9.ED.15Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.ED.15Wikidata (CC0) |