Detailed information
Species
Bournonite
Dimensions
42 x 27 x 22
mm
Locality
Viboras Mine, Machacamarca Cornelio Saavedra Province Potosí Department, Bolivia
Condition
No recorded repairs
Intergrown cog-like crystals of Bournonite with a little attached granular Quartz and Limonite from the Viboras mine in the Machacamarca mining district of Cornelio Saavedra Province, Bolivia. The Bournonite forms excellent classic cog wheels of gunmetal-grey with a bright metallic lustre. The largest crystal measures 2.9 cm long x 0.9 cm wide and up to 2 cm deep and is joined with two sub-parallel, similar but smaller crystals. A superb example of Bournonite, commonly known as 'cog-wheel ore'.