Coboltoan calcite with malachite. Katanga Copper Crescent, Katanga (Shaba), Democratic Republic of Congo (Zaïre). photo Heritage Auctions

It is no surprise that minerals predominantly display colors involving one of the "earth tones" - orange, brown, black, tan, etc. Once in a while Mother Nature sticks a Joker into the deck: something so outlandishly extreme in coloration that onlookers are tempted to say -"That just can't be real!" Good examples of Cobaltoan Calcite are one of those zingers. Here a fairly normal, golden hued Calcite matrix is thinly over-coated by a second generation of Calcite strongly infused with Cobalt, a metal that the DRC is a main source for. This infusion produces a tint so exotic that it just has to be bogus. Well, it isn't. In this case the Cobalt concentration is higher than normal for this material, but still - 100% natural. The bright Cobalt based color being present only in the exterior portions of the Calcite crystals makes them appear to be outlined in hot pink. Just for a little extra 'punch' there are bright green patches of Malachite scattered about the upper surface of the piece. Other than a small bit of flaking on one side, the condition of this psychedelic confection is excellent and it measures: 4 inches by 3 inches by 2 inches (10.2 x 7.6 x 5.1 cm). There is a custom labeled base. Estimate: $80,000 - $90,000.

Heritage Auctions. 2012 May 20 Natural History Signature Auction- New York