Rare amethyst geode with large calcite bloom and red goethite rim

A rare amethyst geode from Uruguay with a large calcite flower and a red goethite rim. Three minerals in one geode, a textbook stratigraphic specimen.

The three-mineral constellation in one geode documents a complex mineralization history. Goethite (iron hydroxide) from the first solution phase colors the rim red. The main amethyst phase fills the geode volume with violet points. Calcite, as a later phase, grew as a flower on already formed quartz points.

Goethite rims are a deposit-related collector's characteristic in the Uruguayan amethyst market. They document iron-rich early solutions that later oxidized to goethite.

The calcite flower in the center of the geode is a distinctive scalenohedron aggregation. It contrasts white-transparent against the violet amethyst background and makes the succession of the three phases directly visible.

A Uruguayan collector's item with a three-mineral genesis, documented stratigraphy, and museum-worthy detail.