Ludwigite
Mg2Fe3+O2(BO3)IMA symbol: Ldwgrandfathered
Ludwigite is a borate mineral with the formula Mg2Fe3+O2(BO3), crystallizing in the orthorhombic system. It has a Mohs hardness of 5, typically black, brown, green or violet in color, with a silky luster, a specific gravity of 3.91-4.02.
Photos
Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P b a m |
| Cell (Å, °) | a = 9.26, b = 12.294, c = 3.0236; α = 90, β = 90, γ = 90 |
| Cell volume | 344.214 ų, Z = 2 |
| Axial ratios | 0.7532:1:0.2459calculated from COD 9014098 |
| Source structure | COD 9014098 (Crystallography Reports, 2002) — 1 of 3 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.561 | 5.121 | 2.532 | 2.038 | 2.172 | 1.911 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 99.1 | 94.4 | 70.6 | 36 | 34.4 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9014098; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.687 g/cm³calculated from COD 9014098 |
|---|---|
| Hardness (Mohs) | 5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3.91-4.02 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, brown, green, violetsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | silkysingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Classification
| Nickel-Strunz (10th) | 6.AB.30Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 6.AB.30Wikidata (CC0) |