Great dark amethyst geode pair from Brazil

A dark amethyst geode pair from Brazil, with an unusually deep violet coloration. Brazilian material with a dark hue is rarer than the more typical light pastel variety.

Amethyst crystallized in the volcanic geodes of the Serra-Geral Basalt Formation from silica-rich solutions over millions of years. The depth of the coloration depends on iron concentration and radiation exposure. Dark Brazilian amethysts indicate higher iron concentrations in the respective geode.

Geode pairs are created by controlled splitting of the geode along its axis of symmetry. Both halves show the mirror-image growth geometry of the original cavity's inner wall.

Brazilian deposits in Rio Grande do Sul yield a wide spectrum of amethyst colorations, from light lilac to deep violet. Dark pairs like this are relevant to collectors as a premium Brazilian category.

A collector's item with classic geode pair form and deep Brazilian coloration.