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).
In addition to the magnetite which forms both massive lodestone and crystals, the complex is strewn with odd and rare minerals, and is the type locality for five mineral species.
The matrix consists of an extremely fine-grained groundmass with fine-to coarse-grained megacrysts of biotite, diopside, aegerine-augite, orthoclase, magnetite, apatite, and nepheline.
