Hydromagnesite
Mg5(CO3)4(OH)2·4H2OIMA symbol: Hmgsgrandfathered
Hydromagnesite is a carbonate or nitrate mineral with the formula Mg5(CO3)4(OH)2·4H2O, crystallizing in the monoclinic system. It has a Mohs hardness of 3-5, typically white in color, with an earthy or pearly luster, a specific gravity of 2.145-2.18. Its streak is white.
Photos
.jpg){kind=link}
.jpg){kind=link}
Crystallography
| Crystal system | monoclinic crystal systemWikidata (CC0) |
|---|---|
| Space group | P 1 21/c 1 |
| Cell (Å, °) | a = 10.105, b = 8.954, c = 8.378; α = 90, β = 114.44, γ = 90 |
| Cell volume | 690.118 ų, Z = 2 |
| Axial ratios | 1.1285:1:0.9357calculated from COD 9007620 |
| Source structure | COD 9007620 (Acta Crystallographica, Section B, 1977) |
Powder X-ray diffraction (calculated)
| d (Å) | 5.806 | 5.804 | 2.903 | 9.2 | 6.416 | 4.189 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 94.5 | 85.7 | 77.3 | 72.5 | 49.7 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9007620; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.25 g/cm³calculated from COD 9007620 |
|---|---|
| Hardness (Mohs) | 3-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.145-2.18 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | earthy, pearly, silky, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 467.64 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Mg 25.99%, C 10.27%, O 61.58%, H 2.16% |
Classification
| Nickel-Strunz (10th) | 5.DA.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.DA.05Wikidata (CC0) |