Hemimorphite
Zn4(Si2O7)(OH)2·H2OIMA symbol: Hmpapproved
Hemimorphite is a silicate mineral with the formula Zn4(Si2O7)(OH)2·H2O, crystallizing in the orthorhombic system. It has a Mohs hardness of 4.5-5, typically white, brown, green or yellow in color, with an adamantine or pearly luster, a specific gravity of 3.4-3.5. Its streak is white.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | I m m 2 |
| Cell (Å, °) | a = 8.366, b = 10.714, c = 5.113; α = 90, β = 90, γ = 90 |
| Cell volume | 458.3 ų, Z = 4 |
| Axial ratios | 0.7808:1:0.4772calculated from COD 1549773 |
| Source structure | COD 1549773 (Proceedings of the Japan Academy, Series B, 1978) — 1 of 13 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.099 | 3.285 | 2.556 | 2.928 | 2.399 | 6.594 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 60.1 | 44.9 | 41.1 | 40.5 | 27.6 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 1549773; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.622 g/cm³calculated from COD 1549773 |
|---|---|
| Hardness (Mohs) | 4.5-5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3.4-3.5 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, green, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) whitesingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | adamantine, pearly, vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 481.83 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Zn 54.3%, Si 11.66%, O 33.21%, H 0.84% |
Classification
| Nickel-Strunz (10th) | 9.BD.10Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.BD.10Wikidata (CC0) |
| Dana (8th) | 56.1.2.1Wikidata (CC0) |