Idrialite

Idrialite, or Idrialine, is a soft, orthorhombic hydrocarbon mineral, chemical formula: 4[C22 H14]. It is usually greenish yellow to light brown in colour with bluish fluorescence. It can be found mixed with clay, pyrite and gypsum associated with cinnabar in the Idria region, Slovenia. Its combustibility gave rise to the term "inflammable cinnabar", which is one of its synonyms.