Well formed metallic crystals of Bournonite from one of Cornwall's classic locations for the species, Wheal Boys. The Bournonite forms tabular crystals measuring to 0.9cm. There are several other areas on the specimen with well formed crystals of Bournonite. The matrix is a base of white Quartz in which linear cavities are lined with brown-red-yellow sparkling crystals of Sphalerite. Sparsely scattered in some of the cavities are metallic silvery platy micro-crystal groups of rare Semseyite, and acicular micro-crystals Stibnite/Boulangerite. The specimen also carries areas of granular Galena. A complex specimen of several species, from the outer low temperature zones of the Cornubian Orefield.