Grape Agate is the name given to the botryoidal form of Purple Chalcedony that has recently been discovered in Indonesia. So far there has been only one locality found. Colour's range from dark purple to a light lilac or lavender in its natural form, in the tumbled form there maybe dark areas which is the matrix which is hard not to include in the tumblestone as the actual grape agate in natural form is made up of tiny crystals. Natural GRAPE AGATE CHALCEDONY specimen from Indonesia. This is a amazing piece is from my private collection. Please see my other auctions.