Citrine piece with citrine hedgehog

A citrine specimen with an embedded citrine hedgehog from Brazil. A dense, radially radiating aggregate of golden-yellow micro-points protrudes outwards from the polished cut surface, like erect quills.

Radially radiating hedgehog aggregates form when the solution saturation in a small cavity pocket suddenly changes. Countless microcrystals germinate simultaneously from a central growth point. The result visually resembles erect hedgehog quills.

Brazilian geodes from Rio Grande do Sul provide this material from the Serra Geral Basalt Formation. The iron substitutions that give citrine its warm gold color are particularly concentrated in the hedgehog's core.

The curatorially preserved rough exterior encloses the polished hedgehog cut surface. The geological stratigraphy is legible from several perspectives, an unusual dual presentation of rough and polished.