Elbaite

Elbaite, a sodium, lithium, aluminium borosilicate, is a mineral species belonging to the tourmaline group. Elbaite forms three series, with dravite, with liddicoatite, and with schorl. Due to these series specimens with the ideal end-member formula are not found occurring natually. As a gemstone, elbaite is reckoned to be one of the most desirable of the tourmaline group because of the variety and depth of its colours and quality of the crystals. Originally discovered on the Island of Elba, Italy in 1913 it has since been found in many parts of the world. In 1994 a major locality was discovered in Canada, at O'Grady Lakes in the Yukon.
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General Information:
 Chemical Formula:
Na(Li,Al)3Al6(BO3)3Si6O18(OH)4
 Composition:
(Molecular Weight = 916.68 gm)
Sodium 2.51 % Na
Lithium 1.89 % Li
Aluminum 19.13 % Al
Silicon 18.38 % Si
Boron 3.54 % B 
Hydrogen 0.44 % H 
Oxygen 54.11 % O 
 Empirical Formula:
NaLi2.5Al6.5(BO3)3Si6O18(OH)4
 Environment:
Granitic pegmatites characterized by hydrothermal replacement.
 Locality:
Island of Elba, Italy.
 Name Origin:
Named after its locality.
Physical Properties:
 Cleavage:
[1011] Indistinct
 Color:
blue, colorless, green, yellow, or white.
 Density:
2.9 - 3.2, Average = 3.05
 Diaphaniety:
Transparent to translucent to opaque
 Habits:
Striated - Parallel lines on crystal surface or cleavage face., Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).,
 Hardness:
7.5 - Garnet
 Luminescence:
Piezoelectric.
 Luster:
Vitreous (Glassy)
 Streak:
white
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