Tetrahedrite Subgroup with Siderite and Sphalerite

Item Description

A rarely seen specimen from Peru featuring a beautiful, prominent, sharp, well-formed, lustrous, dark steel-black colored modified tetrahedral crystal of a member of the Tetrahedrite Subgroup measuring 1.3 cm, sitting aesthetically atop a matrix of Quartz that is covered by light tan colored Siderite rhombs, along with little gemmy green / gold colored crystals of Sphalerite for a nice touch. If you flip the piece over, you can see bright metallic spots of Pyrite/Chalcopyrite mixed into the Quartz. The piece was mined in the 1980s and is one of the very few Tetrahedrites we've had to offer from this area, and certainly one of the most eye-catching. No major damage and very attractive in person. It's hard to find single isolated Tetrahedrite crystals on matrix like this from any Peruvian locality, as they are often tightly intergrown, so this is a special piece and certainly worth adding to any sulfide suite or a collection of Peruvian minerals. This piece comes from the personal collection of Colorado mining legend, Dave Bergman, the maternal grandfather of Brian Kosnar. Dave is now retired from mining, but he worked for decades in various mines underground in Colorado, as a miner, mechanic, engineer, shift boss and foreman. His biggest claim to fame is that he was the foreman and the primary person in charge of mining and specimen recovery at the Sweet Home Mine in Colorado in the 1970s alongside his son-in-law, Rich Kosnar. This project what was the FIRST ever operation for specimen recovery at this historic locality. A full-page photograph of Dave can be seen mining underground at the Sweet Home in on page 58 of Peter Bancroft's book "Gem and Crystal Treasures".