Very deep and wide amethyst geode in great lilac color with hedgehog formations from Brazil

A deep and wide amethyst geode from Brazil, in the typical lilac hue for Brazilian material. Several urchin crystals grow inside, small compact aggregates that grow like spiky balls from the purple wall.

Urchin crystals are formed by radially grown micro-crystallization. A crystallization core serves as a starting point for quartz spikes that grow in all directions. Visually, they resemble sea urchin structures, hence the common name.

Brazilian amethysts from Rio Grande do Sul offer a broader color spectrum than the Uruguayan deposits. Pastel lilac tones, as seen here, indicate reduced iron concentration during crystallization. The depth and width of the geode document slow, undisturbed growth.

The accompanying urchin crystals are collector-relevant. They show that multiple growth modes occurred in parallel within the geode: the main growth along the wall, the urchin phase as a later, detailed generation in individual places.

A collector's item with a pastel color variant and didactically valuable microcrystal structures.