Colorado Gem & Mineral Co. - Rocks for the Rest of Us
Pyrite Concretion
Natural geologic feature of pyrite in black shale concretion. These concretions are found in sizes as large as 5 feet across, but few have the showy pyrite and small sizes like these are even rarer. We predict that this new find will be quickly exploited and become a rarity in the near future.
flattened egg shape.