Beryl
From The Gemology Project
Beryl | |
---|---|
Chemical composition | Be3Al2(SiO3)6 Beryllium aluminum silicate |
Crystal system | Hexagonal |
Habit | Prismatic |
Cleavage | Very difficult in one direction, rarely seen |
Fracture | Conchoidal |
Hardness | 7.25-7.75 |
Optic nature | Uniaxial - |
Refractive index | 1.577-1.583 (+ or - 0.017) |
Birefringence | 0.005-0.009 |
Dispersion | Low, 0.014 |
Specific gravity | 2.72 (+0.18,- 0.05) |
Lustre | Vitreous to resinous |
Pleochroism | Weak to moderate |
Beryl is a beryllium aluminum silicate that occurs in every color of the rainbow. When green, it's an emerald. When blue, it's aquamarine. When pink, it's morganite. There is a raspberry red variety found in Utah called Bixbite. Yellow is heliodor and colorless is goshenite. There is a very rare and costly variety termed riesling beryl, that can be described as pale green colour, with a warm golden yellow flash. Beryl had been used as a physician's tool and gazing stone since ancient times. Those beliefs persist today. Beryl is metaphysically attributed with the ability to cure a number of intestinal and stomach ills, such as nausea, ulcers, and seasickness.