Adamite
Zn2(AsO4)(OH)IMA symbol: Adgrandfathered
Adamite is a phosphate, arsenate, or vanadate mineral with the formula Zn2(AsO4)(OH), crystallizing in the orthorhombic system. It has a Mohs hardness of 3-5, typically colorless, green, red or rose in color, with a vitreous luster, a specific gravity of 4.338. Its streak is white.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P n n m |
| Cell (Å, °) | a = 8.306, b = 8.524, c = 6.043; α = 90, β = 90, γ = 90 |
| Cell volume | 427.846 ų, Z = 4 |
| Axial ratios | 0.9744:1:0.7089calculated from COD 9000521 |
| Source structure | COD 9000521 (American Mineralogist, 1976) — 1 of 6 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 2.974 | 5.949 | 2.694 | 2.465 | 4.887 | 2.456 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 62.1 | 60.2 | 59 | 57.1 | 48.6 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9000521; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 4.452 g/cm³calculated from COD 9000521 |
|---|---|
| Hardness (Mohs) | 3.5single sourceWikidata (CC0) 3-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 4.338 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | colorless, green, red, rose, violet, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 286.74 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Zn 45.62%, As 26.13%, O 27.9%, H 0.35% |
Classification
| Nickel-Strunz (10th) | 8.BB.30Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 8.BB.30Wikidata (CC0) |
| Dana (8th) | 41.6.6.3Wikidata (CC0) |