Finely-crystallized branching group of copper crystals. Because the copper crystals form in very tight seams in basalt, one often finds that the crystallization is not fully developed. Despite the narrow seam in which this one formed (as you can tell from the last measurement above (!)), this one does include nicely defined crystals. The colour and lustre of this piece includes some coppery colour, a little of the bright silvery iridescence seen on of some of these, and also some nice red cuprite coating. Pretty specimen.