Bornite

Mineralogical name for a natural copper ore that tarnishes to various iridescent shades due to oxidation. However, most offered bright blue/purple colored bornite or peacock…

Chiquitanita

Commercial name for a deep green, chromium-containing chalcedony from Bolivia. Similar to the more common chrysoprase, a green nickel-containing chalcedony variety. Chromium chalcedony found in…