Beryl -- Be3Al2(SiO3)6 -- Beryllium aluminum silicate
- Emerald is the green form of the mineral Beryl
- Emerald has a Mohs hardness of 8
- Emerald's specific gravity is about 2.6 - 2.9
- Emerald has a white streak
- Emerald forms in hexagonal crystals
- "Emerald" comes from the Latin word smaragdus, which means "green gem"