Allanite is a silicate containing a large amount of cerium. It is usually black in colour, opaque, and is related to epidote in form and composition. It occurs as a minor constituent of many igneous rocks and is frequently associated with epidote. Found in some magnetic bodies. It has the formulae (Ce,Ca,Y)2(ALFe)3(SiO4) 3(OH) and a relative hardness of 6. It is named after T. Allan who discovered it.
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