I was very surprised to find these! they are curt from Amethyst geodes, by means of a "core sampler" and they are simply lovely! Each cylinder shows the entire structure of a geode; from the colorful Jasper and Agate bed, through the crystalline structure that ends in the sparkly surface.

Warning; These cylinders are more fragile than most of my other tips, and can break due to the crystalline inner structure.