Tiny Tuesday Mineral

We have a shop in Blackheath that sells this sort of thing so I had it in mind for the TT theme of mineral.

I didn't like to go in and start photographing their wares but figured I'd have half a chance through the window.
So I went down after closing and got this.
It looks worryingly tooth like to me, and just so happens to be next door to the dentist......

Many thanks to Thisislife for hosting this month.