very dark Uruguayan amethyst geode with large calcite and agate flower

A very dark Uruguayan Amethyst Geode with a large Calcite crystal and an agate flower. Three mineral generations in a single cavity, each with its own optics and color signature.

The agate flower is a radially-bladed microcrystal aggregate from the first solution phase of the geode. It sits on the geode wall like a petrified bud.

In the main amethyst phase, deep violet points then grew from the iron-containing solution. The calcite crystallized as the third generation on the finished quartz points.

Uruguayan amethyst from the Arapey Basalt Formation is considered the darkest amethyst variety worldwide. Three-mineral constellations in a geode are a premium collector's feature.

A Uruguayan collector's item with three-mineral genesis, premium color, and documented constellation complexity.