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Download hereGENERAL DESCRIPTION
Elbaite is an hydrated lithium and sodium aluminium borosilicate, belonging to the group of tourmalines.
The elbaite is a rare variety of tourmaline. It is presented out of prismatic crystals with a triangular section, often transparent, with various colours, having piezoelectric and pyrolectric properties.
Pure, the elbaite is colourless (it is called then "achroïte"), but the coloured varieties are used in jewellery.
One distinguishes mainly rubellite, which is pink to red-mauve, verdelite (green, dark and bluish green), the blue indicolite. Colouring can vary from one end of a crystal to the other. Through cross sections, colour zones traduces growth patterns.
Very beautiful crystals arise from Brazil (Minas Gerais), Siberia (Adun-Cholon), Angola and Mozambique, Madagascar (Antsentsindrano, Sahatany valley, Ambatofinandrahana...), USA (California), Afghanistan (Paprok) and the Elba Island (Italie). The rubellite variety is found only in the granitic pegmatites. Among the most beautiful specimens of this variety, one can quote those discovered in the Jonas mine in Itatiaia in Brazil. Hundreds of gemmy crystals were extracted from this mine, and sometimes of foundric size.
One also finds very beautiful crystals from deposits located in California, such as Pala and Mesa Grande, in San Diego county. Indicolite is a very rare blue variety. The colour of tourmalines is highly variable. The precise origin of these colours complex and is not yet completely understood. The indicolites of the mines of Morro Redondo and Paraiba in Brazil are of "electric" colour, blue to green "neon". They contain copper. As this deposit is highly protected and that it produces very rare varieties of indicolites, any carat is sold at high prices.
Verdelite is also rather rare, the elements responsible for its green colouring are not well known, that perhaps manganese, iron and/or chromium as the colour palette ranges from green olive to very dark green.
In France, elbaïte is rather rare, one finds it in pegmatites with lepidolites of the Chédeville quarry in Ambazac (Haute-Vienne, Ferté Macé (Flowering ash), Castelnau de Brassac in the Tarn or in the area of Chanteloube in Haute-Vienne. It is also known in the Tamanoir range in French Guyana.
The type is not definable because this species was already known before the conditions of deposit of the types were defined.
HISTORY : Named after its type-locality: Elba Island, Italy
Species first described in 1913 by Vladimir Ivanovich Vernadsky (1863-1945), Russian scientist, founder of geochemistry
Type-locality : San Piero In Campo, Elba Island, Tuscany, Italy
CHEMICAL FORMULA : Na(Al,Li)3 Al6(BO3)3 Si6O18 (OH)4
CRYSTAL SYSTEM : Rhomboedric
COLOR : Pink to red, mauve, green
DIAPHANIETY : Transparent to translucent
LUSTER : Vitreous to resineous
STREAK : White
MORPHOLOGIE : Prismatic acicular crystals
HARDNESS : 7
CHEMICAL CLASS: 3,069
DENSITY : VIII - Silicates
GROUP : Tourmaline
STRUNZ CLASS BEFORE 2001 : 8/E.19-10
STRUNZ CLASS AFTER 2001 : 9.CK.05
