Amethyst

Artigas, Artigas Department, Uruguay

18 x 24 x 16 cm (7⅛ x 9½ x 6¼ inches). 6.15 kilograms (13.6 pounds).

https://www.sothebys.com/en/buy/auction/2025/natural-history-2/amethyst

This is a remarkable example of Amethyst, sourced from the Artigas Department in northern Uruguay. In a region best known for its prolific production of geodes (typically cavities lined in tiny amethyst crystals), this piece stands apart as a genuine outlier of form, scale, and saturation—a discovery that significantly expands the known potential of the locality.

Anchoring the piece are two commanding crystals—each in excess of three inches in diameter—rising with architectural clarity above a matrix of crystals. The saturation is nothing short of electric: an intense, deep grape jelly purple, with extraordinary internal brightness and near-gem transparency. This level of crystallographic development and chromatic intensity is virtually unheard of in Artigas material, where most crystals rarely exceed one inch and often lack the optical clarity seen here.

The crystal morphology is sharply trigonal, with steep, lustrous pyramidal terminations and highly reflective prism faces. The crystals are spatially distinct, well-separated, and more closely resemble elite African or Mexican examples than the more common clustered habit typical of Uruguay.

Formed approximately 140 to 130 million years ago, during the early Cretaceous Period, these crystals grew slowly in silica-rich hydrothermal fluids that percolated through cavities in the basaltic crust. These vesicles—residual gas bubbles formed during volcanic activity—created the perfect sealed environments for sustained crystal growth. And while nature required over 100 million years to craft this piece, it was not until ca. 2015 that it was finally unearthed by man—a geologic masterpiece revealed in the modern era.