Bournonite (“cogwheel”) George Robertson large Pyrite pseudomorph after compressed

large Pyrite pseudomorph after compressed rhombohedra of Siderite which is associated with sharp

It’s incomplete on the back where it came off the matrix

This piece really does have it all

or Russian minerals

Bournonite (“cogwheel”) George Robertson large Pyrite pseudomorph after compressedI have to say up front that this piece simply is better than the photos indicate. The HIGH luster of the faces made it difficult to photograph. The specimen is in great shape overall, and the robust crystals with their sharp, well defined surfaces are very hard to find from this mine. The piece is twinned and shows the classic "cogwheel" shape that was made famous by the classic specimens from Cornwall, England. Great quality on the display side, and