Crystal Lab › Silicates & minerals
Beryl Be₃Al₂Si₆O₁₈
Cyclosilicate · space group P6/mcc (No. 192) · Z = 2
Symmetry elements and Wyckoff positions (interactive)
Beryl in P6/mcc
SettingLoading the group…
x = 0.10, y = 0.17, z = 0.08
Unit cell
- Lattice constants
- a = 9.208 Å, b = 9.208 Å, c = 9.188 Å; α = 90°, β = 90°, γ = 120°
- Cell volume
- 674.7 ų
- Atoms in the cell
- 58 (Be 6, Al 4, Si 12, O 36)
- Formula units Z
- 2
- Calculated density
- 1.82 g cm⁻³
- Shortest contact
- 1.594 Å
Coordination
- Be
- CN 4 at 1.66 Å (4 O)
- Al
- CN 6 at 1.91 Å (6 O)
- Si
- CN 4 at 1.59 Å (4 O)
- O
- CN 2 at 1.59 Å (1.33 Si + 0.67 Be)
About the structure
- Six-membered Si₆O₁₈ rings stacked along c to form open channels, linked sideways by BeO₄ tetrahedra and AlO₆ octahedra.
- Emerald (Cr³⁺) and aquamarine (Fe) are beryl with trace colouring ions; the channels can hold water and alkali ions.
- Coordinates from the Crystallography Open Database, entry 9001018 (open data); hydrogen and water sites with partial occupancy below 0.5 are left out.
Atom positions (fractional, one cell)
| Atom | x | y | z |
|---|---|---|---|
| Be | 0.5000 | 0.0000 | 0.2500 |
| Be | 0.5000 | 0.5000 | 0.7500 |
| Be | 0.5000 | 0.5000 | 0.2500 |
| Be | 0.0000 | 0.5000 | 0.7500 |
| Be | 0.0000 | 0.5000 | 0.2500 |
| Be | 0.5000 | 0.0000 | 0.7500 |
| Al | 0.3333 | 0.6667 | 0.2500 |
| Al | 0.6667 | 0.3333 | 0.7500 |
| Al | 0.3333 | 0.6667 | 0.7500 |
| Al | 0.6667 | 0.3333 | 0.2500 |
| Si | 0.3876 | 0.1159 | 0.0000 |
| Si | 0.6124 | 0.7283 | 0.5000 |
| Si | 0.3876 | 0.2717 | 0.5000 |
| Si | 0.7283 | 0.6124 | 0.0000 |
| Si | 0.2717 | 0.3876 | 0.0000 |
| Si | 0.8841 | 0.6124 | 0.5000 |
| Si | 0.1159 | 0.3876 | 0.5000 |
| Si | 0.1159 | 0.7283 | 0.0000 |
| Si | 0.8841 | 0.2717 | 0.0000 |
| Si | 0.2717 | 0.8841 | 0.5000 |
| Si | 0.7283 | 0.1159 | 0.5000 |
| Si | 0.6124 | 0.8841 | 0.0000 |
| O | 0.3103 | 0.2369 | 0.0000 |
| O | 0.6897 | 0.9266 | 0.5000 |
| O | 0.3103 | 0.0734 | 0.5000 |
| O | 0.9266 | 0.6897 | 0.0000 |
| O | 0.0734 | 0.3103 | 0.0000 |
| O | 0.7631 | 0.6897 | 0.5000 |
| O | 0.2369 | 0.3103 | 0.5000 |
| O | 0.2369 | 0.9266 | 0.0000 |
| O | 0.7631 | 0.0734 | 0.0000 |
| O | 0.0734 | 0.7631 | 0.5000 |
| O | 0.9266 | 0.2369 | 0.5000 |
| O | 0.6897 | 0.7631 | 0.0000 |
| O | 0.4985 | 0.1456 | 0.1453 |
| O | 0.5015 | 0.6471 | 0.6453 |
| O | 0.4985 | 0.3529 | 0.3547 |
| O | 0.6471 | 0.5015 | 0.8547 |
| O | 0.3529 | 0.4985 | 0.1453 |
| O | 0.8544 | 0.5015 | 0.6453 |
| O | 0.1456 | 0.4985 | 0.3547 |
| O | 0.1456 | 0.6471 | 0.8547 |
| O | 0.8544 | 0.3529 | 0.1453 |
| O | 0.3529 | 0.8544 | 0.6453 |
| O | 0.6471 | 0.1456 | 0.3547 |
| O | 0.4985 | 0.1456 | 0.8547 |
| O | 0.5015 | 0.8544 | 0.1453 |
| O | 0.4985 | 0.3529 | 0.6453 |
| O | 0.5015 | 0.6471 | 0.3547 |
| O | 0.3529 | 0.4985 | 0.8547 |
| O | 0.6471 | 0.5015 | 0.1453 |
| O | 0.1456 | 0.4985 | 0.6453 |
| O | 0.8544 | 0.5015 | 0.3547 |
| O | 0.8544 | 0.3529 | 0.8547 |
| O | 0.1456 | 0.6471 | 0.1453 |
| O | 0.6471 | 0.1456 | 0.6453 |
| O | 0.3529 | 0.8544 | 0.3547 |
| O | 0.5015 | 0.8544 | 0.8547 |
Z, coordination numbers, distances, density and packing on this page are computed from these coordinates.