Organic mineral

Organic minerals are rare, and tend to have specialized settings such as fossilized cacti and bat guano.

[5] Other PAH compounds appearing as minerals include fluorene as kratochvilite; and anthracene as ravatite.

[5][6][7] Others are mixtures: curtisite contains several PAH compounds, including dibenzofluorine, picene, and chrysene, while the most common components of idrialite are tribenzofluorenes.

A large fraction have water molecules attached; examples include weddellite, whewellite, and zhemchuzhnikovite.

Oxalates are often associated with particular fossilized biological materials, for example weddellite with cacti; oxammite with guano and egg shells of birds; glushinskite with lichen; humboldtine, stepanovite and whewellite with leaf litter; and humboldtine, stepanovite and whewellite with coal.

Where plant material such as tree roots interacts with ore bodies, one can find oxalates with transition metals (moolooite, wheatleyite).

[7] Urea derived from bat guano and urine also occurs as a mineral in very arid conditions.

Hazen et al. predict that at least three more PAH crystals (pyrene, chrysene and tetracene) should occur as minerals.