Amethyst druse with a colorful agate rim

An amethyst geode with a colorful agate rim from Uruguay. A classic two-layer stratigraphy with a multicolored banded outer rim.

The colorful agate rim documents a particularly complex first mineralization phase. Several trace element zones alternate, producing the characteristic multi-color banding. Typical colors are red (hematite), orange (goethite), gray-white (pure chalcedony), and occasionally green (chlorite traces).

Uruguayan amethyst from the Arapey Basalt Formation provides the material. The pronounced vertical geode geometry with a compact base makes the piece a slender columnar geode form.

The polished cut surface vividly highlights both mineralization layers. Multi-color agate on the outside, deep violet amethyst on the inside.