AXINITE, a mineral consisting of a complex aluminium and calcium boro-silicate; the calcium is partly replaced in varying amounts by ferrous iron and manganese, and the aluminium by ferric iron; the formula is HCa3BAl2(SiO4)4. The mineral was named (from aEive, an axe) on account of the characteristic thin wedge-like form of its an orthic crystals. The colour is usually clove-brown, but rarely it has a violet tinge. The best specimens are afforded by the beautifully developed transparent crystals, found at Le Bourg d'Oisans in Dauphine. The spe cific gravity is 3.28. The hard ness of 61.-7, combined with the colour and transparency, renders axinite applicable for use as a gemstone, the Dauphine crystals being occasionally cut for this purpose.