Metallic intergrown crystals of Bournonite from one of Cornwall's classic locations for the species, Wheal Boys. The Bournonite forms a 2.3cm by 1.5cm area of intergrown tabular crystals. There are several other areas on the specimen with well formed microcrystals of Bournonite. The matrix is a base of white Quartz in which linear cavities are lined with deep maroon red sparkling crystals of Sphalerite. Sparsely scattered in some of the cavities are metallic silvery platy micro-crystal groups of rare Semseyite. The specimen also carries areas of granular Galena.