Chrysoberyl
BeAl2O4IMA symbol: Cbrlgrandfathered
Chrysoberyl is an oxide or hydroxide mineral with the formula BeAl2O4, crystallizing in the orthorhombic system. It has a Mohs hardness of 8.5, typically white, brown, green or red in color, with a vitreous luster, a specific gravity of 3.5-3.84. Its streak is red.
Photos
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Crystallography
| Crystal system | orthorhombic crystal systemWikidata (CC0) |
|---|---|
| Space group | P n m a |
| Cell (Å, °) | a = 9.4082, b = 5.479, c = 4.4288; α = 90, β = 90, γ = 90 |
| Cell volume | 228.294 ų, Z = 4 |
| Axial ratios | 1.7171:1:0.8083calculated from COD 9010926 |
| Source structure | COD 9010926 (Physics and Chemistry of Minerals, 2007) — 1 of 14 structures |
Powder X-ray diffraction (calculated)
| d (Å) | 1.617 | 3.234 | 2.088 | 2.559 | 2.261 | 2.077 |
|---|---|---|---|---|---|---|
| I/I₀ | 100 | 92.8 | 92.7 | 55.1 | 48.9 | 48 |
xrd-v1: CuKa1 1.5406A, 2theta 5-90, top10, Imax=100, no DW/PO. Computed from COD 9010926; idealized occupancies, no preferred orientation.
Physical properties
| Density (calculated) | 3.709 g/cm³calculated from COD 9010926 |
|---|---|
| Hardness (Mohs) | 8.5single sourceWikidata (CC0) 8.5single sourceDana, System of Mineralogy, 6th ed. (1892) |
| Specific gravity | 3.5-3.84 g/cm3corroboratedDana, System of Mineralogy, 6th ed. (1892) |
| Color | brown, green, red, white, yellowsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Streak | whitesingle sourceWikidata (CC0) redsingle sourceDana, System of Mineralogy, 6th ed. (1892) |
| Luster | vitreoussingle sourceDana, System of Mineralogy, 6th ed. (1892) |
Chemistry (calculated)
| Molecular weight | 126.97 g/molcalculated from the IMA formula |
|---|---|
| Composition (wt%) | Be 7.1%, Al 42.5%, O 50.4% |
Classification
| Nickel-Strunz (10th) | 4.BA.05Wikidata (CC0) |
|---|---|
| Nickel-Strunz (9th) | 4.BA.05Wikidata (CC0) |
| Dana (8th) | 7.2.9.1Wikidata (CC0) |