Re: Could a fossilized unopened (oyster) shell still contain a pearl?

Could a fossilized oyster still contain a pearl?

I'm told that I appear to be the best match among the mad scientists to 
answer this question, but I have to admit that I really don't know. If you 
will indulge me, I'll do the best that I can.

The question that you ask lies properly within the realm of Taphonomy, 
which is the study of how living things become incorporated into the fossil 
record. My experience deals with vertebrate paleontology and so I don't 
know much about invertebrates (such as an oyster). I suspect that an 
important part of this question deals with oyster physiology , how a pearl 
is formed, and how old oysters are in the fossil record. 

When something fossilizes it is actually turning into stone. Dissolved 
minerals gradually replace all the original parts of the organic structure. 
Most of the fossil shells that I have seen (typically 400+ million years 
old) have turned completely into stone. Since a pearl is basically shell 
material, I would suspect that it too would turn to stone if given enough 
time. However, sometimes we dig up things that we call fossils, but that 
have not been completely mineralized. In that case, a pearl might persist 
in a relatively unmodified form. 

In any case, if an oyster that contains a pearl dies and starts to become 
fossilized, I can foresee no reason why the pearl would not remain.