Formula: Be3Al2Si6O18
Crystal: Beryl crystals are usually hexagonal.
Percent Composition:
| Element | Percent Composition by Mass | Percent Composition by Number |
| Beryllium | 5.0% | 10.3% |
| Aluminum | 10.1% | 6.9% |
| Silicon | 31.3% | 20.7% |
| Oxygen | 53.6% | 62.1% |
This is a model of beryl's structure:
(from: http://www.ill.fr/di f/3D-crystals/minerals.html)
Bonding: In the backbone of beryl's structure all the bonds are single bonds.