| Material name | Amethyst | |||||
| Composition | SiO2 (trace Fe ion) | |||||
| Chemical formula weight | 60.08 | |||||
| System | Trigonal | |||||
| Temperature (ºC) | r.t. | |||||
| a (Å), b (Å), c (Å) | 4.921(1) | 4.921(1) | 5.4163(8) | |||
| α (deg), β (deg), γ (deg) | 90 | 90 | 120 | |||
| Unit cell volume (Å3) | 113.6 | |||||
| Calculated density (g/㎝3) | 2.63 | |||||
| Z | 3 | |||||
| Space group | P3121 (No.152) | |||||
| atom | site | g | x/a | y/b | z/c | B (Å2) |
| Si | 3a | 1 | 0.4698(2) | 0 | 1/3 | 0.363 |
| O | 6c | 1 | 0.4151(5) | 0.2675(4) | 0.2139(1) | 0.80 |
| Comment | B values were calculated on the basis of Ueq values in the reference. | |||||
Reference: J. Glinnemann, H.E. King, H. Schulz, T. Hahn, S.J. la Placa, and F. Dacol, Zeitschrift für Kristallographie, 198, 177 (1992).