Excellent cogwheel-twinned bournonite crystals comprise this piece. On the left hand side there are small translucent sphalerite crystals, and I believe the minor blue colouration is likely micro rosasite, but I have not had it tested. The main bournonite crystals were naturally broken from a larger face or matrix, sometime late in their formation history, and the uneven backside is dusted with secondary micro minerals, including micro crystals of cerussite and sphalerite. In excellent condition with edge-chipping in a couple places.These are particularly sharp bournonite crystals for this locality – very nice.