Every so often we get these satisfyingly round gypsum balls in stock. These are highly collectable, which is why there has been one in every crystal collection recycled by TSC so far.

This formation is known as the desert rose. These mineralisation form in extremely arid areas. When the land is so dry that when rain does come, the earth is too compacted for it to penetrate the ground. The water sits on top and mixes with the local minerals. Eventually the water evaporates and you get the desert rose.

These two are in great condition. I think there's a third somewhere, too.