Elbaite, a sodium, lithium, aluminium boro-silicate, with the chemical composition Na(Li1.5Al1.5)Al6Si6O18(BO3)3(OH)4,[4] is a mineral species belonging to the six-member ring cyclosilicate tourmaline group.

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.

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.

Elbaite is allochromatic, meaning trace amounts of impurities can tint crystals, and it can be strongly pleochroic.

Microscopic acicular inclusions in some elbaite crystals show the cat's eye effect in polished cabochons.