Assorted Color Agate Geode Lamp with Cord and 7-Watt Bulb - Choose your color! Uniqueness Guaranteed: Every item is one-of-a-kind, making them ideal for all projects or designs. Avg Size Range: (6 to 8 Inches Tall) Sizes Vary 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. Some of these agates have been dyed to enhance their color. Handmade items vary in size, shape, and color when selected randomly (the highest quality items are chosen first). They'll be as beautiful as those in the photos.