Smithsonite
Zn(CO3)IMA symbol: Smtgrandfathered
Smithsonite is a carbonate or nitrate mineral with the formula Zn(CO3), crystallizing in the trigonal system. It has a Mohs hardness of 5, typically white, blue, brown or gray in color, with a pearly or vitreous luster, a specific gravity of 4.3-4.45. Its streak is white.
Photos
_02_by_shakko.JPG){kind=link}
_01_by_shakko.JPG){kind=link}
Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | R -3 c :H |
| Cell (Å, °) | a = 4.6526, b = 4.6526, c = 15.0257; α = 90, β = 90, γ = 120 |
| Cell volume | 281.68 ų, Z = 6 |
| Axial ratios | 1.0000:1:3.2295calculated from COD 9017357 |
| Source structure | COD 9017357 (Zeitschrift fur Kristallographie, 1981) — 1 of 2 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.748 | 3.551 | 1.704 | 2.326 | 1.946 | 1.702 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 49.6 | 34.1 | 26 | 23.2 | 20.9 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9017357; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 4.415 g/cm³calculated from COD 9017357 |
|---|---|
| Hardness (Mohs) | 5single sourceWikidata (CC0) 5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 4.3-4.45 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | blue, brown, gray, green, whitesingle 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 | 125.42 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Zn 52.15%, C 9.58%, O 38.27% |
Classification
| Nickel-Strunz (10th) | 5.AB.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.AB.05Wikidata (CC0) |