Properties
| Category | Beryl variety |
|---|---|
| Formula | Be3Al2(SiO3)6 |
| Crystal system | Hexagonal (6/m 2/m 2/m) Space group: P6/mсc |
| Color | Bluish green to green |
| Crystal habit | Massive to well Crystalline |
| Cleavage | Imperfect on the |
| Fracture | Conchoidal |
| Mohs scale hardness | 7.5–8 |
| Luster | Vitreous |
| Streak | White |
| Diaphaneity | Transparent to opaque |
| Specific gravity | Average 2.76 |
From the Wikipedia article
Emerald is a gemstone and a variety of the mineral beryl (Be3Al2(SiO3)6) colored green by trace amounts of chromium or sometimes vanadium. Beryl has a hardness of 7.5–8 on the Mohs scale. Most emeralds have many inclusions, so their toughness is classified as poor. Emerald is a cyclosilicate. It occurs mainly in association with quartz, muscovite, albite, schorl, microcline, fluorite, smoky quartz and elbaite.
Source
Source record: crystal-compendium/emerald/minerals.json. Fetched from English Wikipedia by the operator 2 October 2026.
https://en.wikipedia.org/wiki/Emerald — revision id 1374144320. Text and properties from Wikipedia, licensed CC BY-SA 4.0.