8GA07 Chalcedony var. Grape Agate
A nice cabinet sized sample of purple grape agate from Indonesia. This one is a bit odd--it combines a zone of lustrous purple orbs with a zone of somewhat included, possibly altered ones. From the back it is rather ugly (bottom left image), so It needs to be displayed as shown in the main photograph, such that the contrast between the purple and white areas is fully visible.
I have seen some reports describing these as amethyst-- I am not sure if there is enough structure beyond the cryptocrystaline orbs to qualify these as "amethyst" and not chalcedony, but at the end of the day these are still pretty interesting specimens.