This is a spectacular open group of superb Bournonite crystals displaying an excellent cogwheel habit, all embedded in a matrix of finely crystallised Freibergite. Things do not get much better when even the matrix is a well crystallised rare sulphosalt! Four major Bournonite crystals dominate the specimen with three of these sitting at the front. Other smaller Bournonite crystals to over 1 cm are distributed throughout the Freibergite. The three main display Bournonites measure approximately 2.2 x 2.2 x 0.7 cm, 2.2 x 1.5 x 1.0 cm and 1.7 x 1.2 x 1.0 cm. All Bournonites are lustrous metallic silver-grey with mirror-flat pinacoid faces and deeply striated/grooved cogwheel prism faces, with some forming interpenetrant pairs. The Freibergite, a complex silver-copper-iron-antimony-arsenic sulphosalt, forms as gunmetal-grey crystals all to about 1 mm across, of which there are many thousand on the specimen. Bournonite is a lead-copper sulphosalt and is classified as a lead-copper antimoniate. A magnificent large miniature, or small cabinet, specimen of Bournonite with Freibergite from Bolivia.
