A radial disk of crystallized pyrite. These “pyrite suns”, as they are known, represent a unique occurrence – they are only known from the coal mines around the southern Illinois town of Sparta. Until recently, their mode of occurrence has been theorized but not well understood. However… there is a new article coming out soon in Rocks & Minerals magazine to explain them, and these are not what anyone thought they were! The explanation is cooler than any theory I had ever heard previously. I won’t spoil the surprise – I can only say watch for the article coming soon!
This piece has a generally silky metallic lustre with a distinctive pattern of raised pyrite crystallization. I almost never comment that specimens look like things, but to me the raised pattern on this piece is so reminiscent of a butterfly, I can’t look at it and not see it! (The second photo is the back side of the specimen). From the Pete Richards collection, acquired at the Rochester Mineralogical Symposium, 1989.
Unfortunately, most of the coal mines in the area are no longer producing, and so it remains a question as to how long we will continue to see these beautiful specimens recovered.