Rare Amethyst Piece with Huge Calcite Point

A rare amethyst specimen from Uruguay, featuring a massive grown calcite spike. The size of the calcite scalenohedron compared to the amethyst background makes this piece a crystallographic sensation.

Amethyst first crystallized in the geode from silica-rich solutions over millions of years. Only after this phase was complete did calcium-carbonate-bearing solutions penetrate the remaining cavity, allowing the calcite spike to grow as a second generation.

The unusual size of the calcite crystal suggests stable solution conditions over long crystallization periods in a sufficiently large residual cavity. Such prominent carbonate associations are relevant to collectors.

Uruguayan material from the Artigas Basin is among the premium deposits worldwide for intensely colored amethyst. Multi-generational pieces like this document the geological stratigraphy of geode genesis.

A collector's item with a crystallographic focus on the prominent calcite element.