Huge rhombohedrons of calcite are coated with iridescent overgrowths of pyrite or perhaps of chalcopyrite. The largest rhomb is over 11 cm across. Just a really unusual specimen! This is a unique specimen, with really outstanding display qualities. I have seen just a few of these in the past trickle out from some (to my knowledge) unnamed and undisclosed location in Hunan Province. 24.5 x 23.7 x 8 cm