Stunning, 5.7" Metallic Bournonite Crystals with Siderite - Bolivia

This is an absolutely stunning, 5.7" wide association of lustrous bournonite, pyrite, quartz, siderite, and iridescent chalcopyrite crystals. It was collected from the Machacamarca mining district (Colavi mining district) of Potosí, Bolivia. The bournonite exhibits the classic "cogwheel" shape and is encrusted in a mixture of the crystals listed above.

This material likely came out of Viboras mine, an active silver mine that produces gorgeous bournonite, quartz, pyrite, and siderite associations. It comes with an acrylic display stand.

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, Chalcopyrite & Siderite
Machacamarca Mining District (Colavi Mining District), Potosí, Bolivia
5.7 x 5"