[carlsonjok]

Originally Posted by steve B

My brother got a few in the middle east when he was there. Local kids pick them up to sell to tourists.

https://en.wikipedia.org/wiki/Desert_rose_(crystal)

Lots of them on etsy,

Bigger more well defined ones are more.

Ooh, Etsy. I hadn't thought of that. Thank you for the suggestion.

To the earlier question as to how they are formed, this site speculates that "The roses formed when barite crystals precipitated from groundwater in the pore spaces between quartz sand grains within the Garber Sandstone. The roses reflect the shapes of the barite crystals, and hence they are cataloged as minerals."