Elbaite (Paraiba tourmaline - Cuprian Elbaite) - Cut Locality: Mavuco, Nampula Province, Mozambique — Photo: Didier Descouens · CC BY-SA 3.0
Elbaite
Also known as: Rubellite (red), Indicolite (blue), Watermelon tourmaline.
The lithium-rich member of the tourmaline group — the source of the most colorful gem tourmalines, from rubellite to watermelon.
Intro adapted from Wikipedia (CC BY-SA).
Elbaite is an IMA-recognized mineral species in the silicate class, with the chemical formula Na(Al₁.₅Li₁.₅)Al₆(Si₆O₁₈)(BO₃)₃(OH)₃(OH).
It crystallizes in the hexagonal crystal system (space group R3m). It is a member of the Tourmaline structural group.
Key properties: Mohs hardness 7.5; specific gravity 2.9–3.1; typically green or pink or blue or red or colorless or yellow or black; white streak; Vitreous to resinous luster; refractive index 1.633; optically uniaxial.
IMA symbol Elb, grandfathered status — known before the IMA’s founding, named in 1913.
Found in granites, granite pegmatites, and some metamorphic rocks; in high-temperature hydrothermal veins; detrital in sediments.
It is found associated with Quartz, albite, lepidolite, microcline, garnet, muscovite, beryl, apatite, spodumene.
The name comes from the occurrence on the Island of Elba, Italy.
Collections: Gemstones, Collector Favorites.