Kutnohorite ps. Calcite, Pyrite, Quartz

Item Description

This is a rare and large pseudomorph from Peru featuring Kutnohorite ps. Calcite. Outwardly it is a perfect geometric rhombohedron that flaunts a mottled very pale to light pink color on the surfaces that has just a slightly rough texture - and that is Kutnohorite, not rhodo or calcite as it looks. The reverse side shows the complexity of the crystal indicating that the pink, Kutnohorite exterior is a thin (perhaps less than 1 mm) veneer cast over a whitish core of Calcite underneath. The pseudomorph atop measures 5.5 cm on its longest edge and is embellished with a small cluster of milky to translucent Quartz crystals to 2 cm on one side and there is an elongate grouping of brassy-yellow Pyrite crystals that adorn the backside and they are variably developed and up to 1 cm in size. A very unusual, yet attractive piece from Peru. One could ask how we know it is not a manganoan calcite (they are in a series, related species) - well, those fluoresce strongly and obviously, from Peru and most other places...Kutnohorite does not.