Bournonite (excellent “cogwheel”) on Pyrite / Locality - Viboras Mine, Machacamarca, Potosi Department, Bolivia


Shipping to United States: Free

Without question, this is one of the finest matrix “cogwheel” Bournonites that I have handled/owned and offered for sale. I honestly don’t keep much from Bolivia for my personal collection, and I almost never keep the best piece from any lot, but this one was really special, so much so that I had to hold on to it for a little while. It remains as one my favorite Bolivian Bournonites that I’ve seen. I have to say up front that the piece is rather difficult to photograph, and it’s simply BETTER IN PERSON. A very good quality, COMPLETE, sharp, lustrous, silvery colored classic “cogwheel”-twinned crystal group is aesthetically flaring off lustrous, golden, octahedral metallic Pyrite matrix. The “cogwheel” is essentially undamaged, save the tiniest of “Wilbers” on the edge. It’s amazing to me that you can see all sides of the “cogwheel” as it’s not buried into the Pyrite matrix, which is EXCEPTIONALLY RARE in my experience with the material. If you’re a Bolivian collector, or a collector of fine quality sulfides/sulfosalt display specimens, then you cannot afford to pass this one up. The piece is priced accordingly for the superb quality, rarity and the fact that it is literally one in several thousand. I cannot recall a comparable Bournonite from Machacamarca, and I can say without fear of contradiction, that this piece is truly one-of-a-kind.

ex. Brian Kosnar collection

Locality: Viboras Mine, Machacamarca, Machacamarca District (Colavi District), Cornelio Saavedra Province, Potosi Department, Bolivia

Specimen Size: 4.0 x 2.7 x 1.7 cm (miniature)
“Cogwheel”: 2.3 x 2.0 cm

Shipping from United States

Processing time

1-3 business days

Estimated shipping times

  • North America : 2 - 5 business days
  • Europe : 7 - 14 business days
  • Australia, New Zealand and Oceania : 10 - 20 business days
  • Asia Pacific : 7 - 14 business days

I'll do my best to meet these shipping estimates, but can't guarantee them. Actual delivery time will depend on the shipping method you choose.

Customs and import taxes

Buyers are responsible for any customs and import taxes that may apply. I'm not responsible for delays due to customs.

Payment Options

Secure options
  • Accepts Etsy gift cards

Returns & Exchanges

I gladly accept returns, exchanges, and cancellations

Just contact me within: 14 days of delivery

Ship items back to me within: 30 days of delivery

Request a cancellation within: 2 days of purchase

But please contact me if you have any problems with your order.

The following items can't be returned or exchanged

Because of the nature of these items, unless they arrive damaged or defective, I can't accept returns for:

  • Custom or personalized orders

Conditions of return

Buyers are responsible for return shipping costs. If the item is not returned in its original condition, the buyer is responsible for any loss in value.

Questions about your order?

Please contact me if you have any problems with your order.