It occurs with calcite, ettringite, wollastonite, larnite, brownmillerite, gehlenite, diopside, pyrrhotite, grossular, spinel, afwillite, jennite, portlandite, jasmundite, melilite, kalsilite and corundum in the limestone xenoliths.
Bauxite is a very common ore which, along with corundum's reasonably high hardness, contributes to corundum's status as a common, inexpensive abrasive.
It largely consists of the mineral corundum (aluminium oxide), mixed with other species such as the iron-bearing spinels, hercynite, and magnetite, and also rutile (titania).
