Fichtelite
Fichtelite is a rare white mineral found in fossilized wood from Bavaria. It crystallizes in the monoclinic crystal system. It is a cyclic hydrocarbon dimethyl-isopropyl-perhydrophenanthrene, C19H34. It is very soft with a Mohs hardness of 1, the same as talc. Its specific gravity is very low at 1.032, just slightly denser than water.