Formation
(1) Magmatic, through early crystalline precipitation and gravitational segregation from mafic to ultramafic melts or as an accessory in intermediate magmatites.
(2) Contact and regional metamorphic, in particular through the decarbonatization of iron-rich sediments or in the course of skarn formation.
(3) Hydrothermal, through precipitation from hot, mineralized solutions in veins or as metasomatic displacement.
