Morganite
From The Gemology Project
Morganite | |
---|---|
Chemical composition | Be3Al2(SiO3)6 Beryllium aluminium silicate |
Crystal system | Hexagonal |
Habit | Prismatic |
Cleavage | Poor, basal |
Fracture | Conchoidal to uneven |
Hardness | 7.5 |
Optic nature | Unixaial - |
Refractive index | 1.58 - 1.60 |
Birefringence | 0.008 - 0.009 |
Dispersion | Low, 0.014 |
Specific gravity | 2.80 - 2.90 |
Lustre | Vitreous |
Pleochroism | Weak to moderate (shades of body color) |
Morganite is the pink, peach or lilac variety of the mineral beryl. It is a beryllium aluminum silicate colored with a trace amount of manganese. The stone was named after the American banker and gem lover, J. P. Morgan, shortly after it was first discovered in 1902 in the Malagasy Republic (Madagascar). Fine examples are currently found in Minas Gerais, Brazil and Madagascar.
Red (bixbite) and pink (morganite) beryls are manufactured using the hydrothermal process by Biron International in Australia. The coloring agent in these synthetics is titanium opposed to manganese in their natural counterparts.