Amethyst Cast after Calcite

Crazy cool Amethyst cast after Calcite from Uruguay that tells a great story! Initially a large, hexagonal-rhombohedral Calcite prism with a rhombohedral termination formed and was subsequently covered by a plethora of glassy, stubby, very pale to medium purple Amethyst crystals. At a later stage, subsequent to the deposition of the Amethyst, fluids came through the cavity and dissolved the the entire Calcite crystal leaving this marvelous cast. We know the initial history of the piece from the very sharply defined mold of the of the original Calcite crystal that left the telltale signs of its morphology. The individual Amethyst crystals are transparent to translucent and are very pale lavender at the base and rapidly transition to a medium purple at the tips locally incorporating what may be tiny (<2mm) clusters of Lepidocrocite during growth. Most of these inclusions are apparent at the back of the cast and less so at the top. There are so many Amethyst crystal faces and the crystals are so glassy and reflective that the entire piece shimmers with any amount of lighting! A spectacular piece with a great story! Ex Ken Roberts' quartz collection.