Duftite (not chalcopyrite) Calcite

This thumbnail specimen from the Tsumeb Mine, Namibia is a very rare example of chalcopyrite in association with calcite and duftite. Chalcopyrite is not often encountered in fine specimens from Tsumeb, and when it does appear, it is typically only in minor presence. Here, however, organic bloom-like growths of chalcopyrite display a striking blue to purple iridescent patina, the result of natural oxidation processes that lend the piece a colourful, metallic shimmer.

The chalcopyrite crystals are perched on sharp calcite rhombohedra, themselves dusted with a carpet of sparkling micro-crystals of green duftite which also exhibits a subtle iridescent sheen.

The calcite–duftite association is among the most famous and desirable parageneses from Tsumeb, known for producing uniquely sharp, green-tinted rhombohedra unlike those from anywhere else in the world. These particular pockets were mostly discovered in the 1960s–early 1970s, and specimens of this distinctive style are now both classic and highly sought after.

Altogether, this is a sublime and unique thumbnail specimen, combining rarity, mineralogical significance, an important addition for any serious Tsumeb suite.