1.9" Iridescent Bournonite Crystals with Pyrite and Siderite - Bolivia

This is a lustrous, 1.9" wide bournonite crystal cluster that's naturally associated with pyrite, quartz, and siderite crystals. It was collected from the Machacamarca mining district (Colavi mining district) of Potosí, Bolivia. The central bournonite crystal is .4" at its thickest spot and exhibits the classic "cogwheel" shape and iridescence in spots.

This material likely came out of Viboras mine, an active silver mine that produces gorgeous bournonite, quartz, pyrite, and siderite associations.

Bournonite is a sulfosalt mineral in the titular bournonite group. It is a trithioantimoniate of antimony, lead, and copper. It can be found all over the world, most commonly in hydrothermal vein deposits and associated with sphalerite or siderite. The steel-gray crystals can form a repeated twinning habit known as cogwheel twinning: it has historically been called wheel-ore by Romanian miners near Baia Mare.

The lead and antimony in the bournonite can be harmful if absorbed into the blood stream by inhalation or ingestion. The crystals won't pose a health hazard just sitting on a shelf, but it's recommended that you wash your hands after handling.

Chemical Formula: PbCuSbS3
Bournonite, Pyrite, Quartz & Siderite
Machacamarca Mining District (Colavi Mining District), Potosí, Bolivia
1.9 x 1.7"