This cabochon is made from a slice of a thunder egg. The patterning is quite unique. There is clear agate with waterline features along with white agate with thin seams of red. Surrounding it on the top and left side is the nice chocolate brown of the thunder egg rind.
The back is not polished.
The size is about 51 mm tall by 29 mm wide by 5 mm thick. the scale photo photo is on a 10mm or 1cm to the square.