Cerianite-(Ce)
Cerianite- is a relatively rare oxide mineral, belonging to uraninite group with the formula. It is one of a few currently known minerals containing essential tetravalent cerium, the other examples being stetindite and dyrnaesite-(La).
Cerianite- is associated with alkaline rocks, mostly nepheline syenites. It may be found in carbonatites. Cerianite- associates with minerals of the apatite group, bastnäsite-group minerals, calcite, feldspar, "fluocerite", "hydromica", ilmenite, nepheline, magnetite, "törnebohmite" and tremolite. It is the most simple cerium mineral known.
For details on crystal structure see cerium(IV) oxide. Both ceria and thoria have a fluorite structure.