Quartz (variety: Amethyst) coating calcite
Sometimes crystals of one mineral grow on top of crystals of a different mineral, producing an overgrowth. In most cases, you can still see the shape of the crystals that were overgrown, even though they may have been completely covered or dissolved. This specimen shows amethyst growing over calcite crystals.
Catalog Number: 149566
Locality: Danialo mine, Rio Grande du Sol