Bournonite (“cogwheel”)I 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

in late 2004 through early 2005

Specimen # BOL711B88

jet-black twinned crystal of Ferberite (twinned along the a{100} face)

one can see a sparkling spherical aggregate of Marcasite on the top (or bottom depending upon the angle) of the twin

ESPECIALLY with any associated minerals

Specimen # BOL711B58

especially on matrix

This is one of the last pieces of this material that I have left so don't pass it by

There are also a few classic “bent” crystals on the piece as well

Specimen # BOL711B145

Better quality than the photos indicate

this one is in great shape and displays well from a few angles