Chemical Formula: Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
Locality: Island of Elba, Italy.
Name Origin: Named for the locality.
Elbaite, a sodium, lithium, aluminium boro-silicate, is a mineral species belonging to the six member ring cyclosilicate tourmaline group, with the following general composituion: Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)3(OH)
Elbaite forms three series, with dravite, with fluor-liddicoatite, and with schorl. Due to these series, specimens with the ideal end-member formula are not found occurring naturally.
As a gemstone, elbaite is a desirable member 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.
Elbaite forms in igneous and metamorphic rocks and veins in association with lepidolite, microcline, and spodumene in granite pegmatites; with andalusite and biotite in schist; and with molybdenite and cassiterite in massive hydrothermal replacement deposits.
Physical Properties
Cleavage: {1011} Indistinct
Color: Blue, Colorless, Green, Yellow, White.
Density: 2.9 – 3.2, Average = 3.05
Diaphaneity: Transparent to translucent to opaque
Fracture: Sub Conchoidal – Fractures developed in brittle materials characterized by semi-curving surfaces.
Hardness: 7.5 – Garnet
Luminescence: Fluorescent, Short UV=weak blue white to blue.
Luster: Vitreous (Glassy)
Streak: white
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