Mineral Specimen: Quartz var. Chalcedony/Amethyst, Indonesia

Mineral Specimen: Amethyst Chalcedony variety of Quartz sourced from Indonesia:
 
An exceptionally rare formation of chalcedony quartz. This specimen has grown as
many individual rounded beads; opaque purple amethyst in a chalcedony growth
structure. It reminds one of effervescent bubbles.