Pyrolusite
MnO2IMA symbol: Pylapproved
Pyrolusite is an oxide or hydroxide mineral with the formula MnO2, crystallizing in the tetragonal system. It has a Mohs hardness of 2-2.5, typically black or gray in color, with a metallic luster, a specific gravity of 4.82. Its streak is black.
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Crystallography
| Crystal system | tetragonal crystal systemWikidata (CC0) |
|---|---|
| Space group | P 42/m n m |
| Cell (Å, °) | a = 4.4041, b = 4.4041, c = 2.8765; α = 90, β = 90, γ = 90 |
| Cell volume | 55.793 ų, Z = 2 |
| Axial ratios | 1.0000:1:0.6531calculated from COD 1514117 |
| Source structure | COD 1514117 (Australian Journal of Chemistry, 1993) — 1 of 8 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.114 | 1.625 | 2.408 | 1.308 | 1.557 | 2.113 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 57.5 | 53.8 | 19.7 | 16.2 | 13.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 1514117; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 5.175 g/cm³calculated from COD 1514117 |
|---|---|
| Hardness (Mohs) | 2-2.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 4.82 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | black, graysingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | blacksingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | metallicsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 86.94 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mn 63.19%, O 36.81% |
Classification
| Nickel-Strunz (10th) | 4.DB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 4.DB.05Wikidata (CC0) |
| Dana (8th) | 4.4.1.4Wikidata (CC0) |