Amethyst cluster on pale chalcedony matrix, Brazil — 493 g

Description

This specimen is an Amethyst cluster showing a small concentration of deep purple crystals toward the centre, with lighter violet crystals around the margins. The crystals form a drusy, light-catching surface set into a translucent pale chalcedony/quartz matrix; the overall outline is irregular and natural-looking. Measuring 8.5 × 7 × 6 cm and weighing 493 g, the cluster sits on a pale, almost chalcedony-like host that provides a soft contrast to the richer purple tones in the crystal centre. Crystals are arranged as a sparkling druse rather than isolated large points, and colour zoning from the deep centre to paler edges is apparent in the visible crystal fabric. Amethyst is the purple variety of quartz (SiO2) and commonly forms as crystalline druses and clusters in silica-rich hosts. This piece displays those typical habits: coloured quartz crystals perched on a more translucent chalcedony/quartz ground.