Colorado Gem & Mineral Co. - Rocks for the Rest of Us
Pyrite Concretion

Pyrite Concretion

  • $90.00



Very large concretion with distinct layers of pyrite crystals. How these formed is really unique. Bubbles of HS gas (from rotting organic material in the mud) at the bottom of a sea(later forming black shale) reacted with the iron and solidified in the mud, later to be found as concretions in the black shale. There won't be a lot more of these because they are found only at the exposures on the contact between layers.