Botryoidal Chalcedony, aka Grape Agate 18 - Sulawesi, Indonesia

Botryoidal Chalcedony, aka Grape Agate, was recently discovered in Indonesia's coastal areas.  Finally allowed to mine and export it, this material has gained popularity in recent years.  This example is fascinating in that it appears to have formed in a spiral.   Weighs in at 1.53 oz, 3"