Grade A Brazilian Agate Geode Slice Uniqueness Guaranteed: Every item is one-of-a-kind, making them ideal for all projects or designs. Listing is for (1 Piece) Avg Size ( 3.5"-4" long x 3/8" thick) Sizes Vary Slightly Material Origin: (Brazil) Agate is a banded variety of chalcedony that forms inside pockets of metamorphic and volcanic rock. The initial layer and the surrounding minerals and conditions affect subsequent layers and give agate its wide variation in appearance. Agate can also bond with quartz crystal while forming, leading to distinctive white banding and exposed crystal druzy. Custom Requests: Have specific preferences? Leave a message with your order, and we'll do our best to accommodate your requests if possible.