Idrialite, a Rare Organic Fluorescent Mineral

The vast majority of fluorescent minerals are composed of inorganic materials. There are a few exceptions, however. Idrialite is one such exception. Idrialite is a rare, organic, hydrocarbon-based mineral having the chemical formula C22H14, and it shows a beautiful fluorescent response under UV ranging from green to orange. This specimen provides an excellent example of this rare organic fluorescent mineral. It was collected from the Culver-Baer mercury mine, Cloverdale, Sonoma Co., California. The size of this piece is 81 x 56 x 46 mm, and it weighs 200 grams.

Idrialite specimen from the Culver-Baer Mine, shown under short wave UV (254 nm).


Same specimen shown under long wave UV (365 nm).


Visible light image of the same specimen. This rock consists of a tan/yellow matrix with blue/grey quartz veins and druse. Minor crystals of purple/red cinnabar are also present. The idrialite appears to be included in the quartz.

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