Witherite
Ba(CO3)IMA symbol: Wthgrandfathered
Witherite is a carbonate or nitrate mineral with the formula Ba(CO3), crystallizing in the orthorhombic system. It has a Mohs hardness of 3-3.75, typically white, gray or yellow in color, with a resinous or vitreous luster, a specific gravity of 4.29-4.35. Its streak is white.
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P m c n |
| Cell (Å, °) | a = 5.3193, b = 8.9056, c = 6.4353; α = 90, β = 90, γ = 90 |
| Cell volume | 304.85 ų, Z = 4 |
| Axial ratios | 0.5973:1:0.7226calculated from COD 9016592 |
| Source structure | COD 9016592 (American Mineralogist, 2012) — 1 of 27 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.724 | 3.662 | 2.152 | 2.592 | 2.019 | 2.63 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 50.7 | 34 | 27.5 | 27.4 | 22.2 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9016592; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 4.279 g/cm³calculated from COD 9016592 |
|---|---|
| Hardness (Mohs) | 3-3.75single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 4.29-4.35 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | gray, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | resinous, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 197.34 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Ba 69.59%, C 6.09%, O 24.32% |
Classification
| Nickel-Strunz (10th) | 5.AB.15Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 5.AB.15Wikidata (CC0) |
| Dana (8th) | 14.1.3.2Wikidata (CC0) |