My wife and I were eating raw Blue Point Oysters at "Shucks" in Omaha and bit into something that looks like a purplish pearl. I was just curious if this was actually a pearl or maybe something else.
It qualifies as a calcareous concretion to some people or a pearl to others, depending on whether it is nacreous. (pearly) A very interesting find and hopefully no one sacrificed a tooth! To be valuable, it needs to be fairly smooth and attractive. Certainly, it is a keepsake that you can pass down in the family. It might look cute in a cage pendant - http://www.firemountaingems.com/itemdetails/H201242FX