Phenakite
Be2(SiO4)IMA symbol: Phkgrandfathered
Phenakite is a silicate mineral with the formula Be2(SiO4), crystallizing in the trigonal system. It has a Mohs hardness of 7.5-8, typically colorless, brown, red or rose in color, with a vitreous luster, a specific gravity of 2.97-3.
Photos
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Crystallography
| Crystal system | trigonal crystal systemWikidata (CC0) |
|---|---|
| Space group | R -3 :H |
| Cell (Å, °) | a = 12.472, b = 12.472, c = 8.251; α = 90, β = 90, γ = 120 |
| Cell volume | 1111.5 ų, Z = 18 |
| Axial ratios | 1.0000:1:0.6616calculated from COD 9001088 |
| Source structure | COD 9001088 (American Mineralogist, 1987) — 1 of 11 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 3.118 | 2.516 | 3.659 | 2.186 | 1.269 | 2.357 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 75.7 | 72.4 | 66.8 | 53.9 | 52.2 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9001088; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 2.961 g/cm³calculated from COD 9001088 |
|---|---|
| Hardness (Mohs) | 7.5-8single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 2.97-3 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, colorless, red, rose, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 110.11 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Be 16.37%, Si 25.51%, O 58.12% |
Classification
| Nickel-Strunz (10th) | 9.AA.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 9.AA.05Wikidata (CC0) |