Magnesite
Mg(CO3)IMA symbol: Mgsapproved
Magnesite is a carbonate or nitrate mineral with the formula Mg(CO3), crystallizing in the trigonal system. It has a Mohs hardness of 3.5-4.5, typically white, brown, gray or yellow in color, with a silky or vitreous luster, a specific gravity of 3-3.12. Its streak is white.
Photos
Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | R -3 c :H |
| Cell (Å, °) | a = 4.6338, b = 4.6338, c = 15.0192; α = 90, β = 90, γ = 120 |
| Cell volume | 279.288 ų, Z = 6 |
| Axial ratios | 1.0000:1:3.2412calculated from COD 9010210 |
| Source structure | COD 9010210 (American Mineralogist, 2007) — 1 of 41 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.742 | 2.103 | 1.7 | 1.701 | 1.338 | 1.938 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 53.5 | 25.6 | 19.1 | 15.3 | 13.7 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9010210; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.008 g/cm³calculated from COD 9010210 |
|---|---|
| Hardness (Mohs) | 3.5-4.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3-3.12 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, gray, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) |
| Luster | silky, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 84.31 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mg 28.83%, C 14.25%, O 56.93% |
Classification
| Nickel-Strunz (10th) | 5.AB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.AB.05Wikidata (CC0) |
| Dana (8th) | 14.1.1.2Wikidata (CC0) |