Rhodochrosite
Mn(CO3)IMA symbol: Rdsapproved
Rhodochrosite is a carbonate or nitrate mineral with the formula Mn(CO3), crystallizing in the trigonal system. It has a Mohs hardness of 3.5-4.5, typically brown, gray, red or rose in color, with a pearly or vitreous luster, a specific gravity of 3. Its streak is white.
Photos
Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | R -3 c :H |
| Cell (Å, °) | a = 4.773, b = 4.773, c = 15.642; α = 90, β = 90, γ = 120 |
| Cell volume | 308.61 ų, Z = 6 |
| Axial ratios | 1.0000:1:3.2772calculated from COD 1548822 |
| Source structure | COD 1548822 (Journal of Chemical Theory and Computation, 2018) — 1 of 8 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.841 | 3.655 | 1.76 | 1.767 | 2.387 | 1.998 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 29.3 | 29.1 | 20.4 | 20.2 | 19.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 1548822; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.711 g/cm³calculated from COD 1548822 |
|---|---|
| Hardness (Mohs) | 3.5-4.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3 g/cm3single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, gray, red, rose, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | pearly, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 114.95 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mn 47.79%, C 10.45%, O 41.76% |
Classification
| Nickel-Strunz (10th) | 5.AB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.AB.05Wikidata (CC0) |
| Dana (8th) | 14.1.1.4Wikidata (CC0) |