What kind of pearl is this and what might it be worth?

[ldelbosque]

I found this pearl wrapped in a cloth in a can of old coins and I wanted to find out what it is and if it has any value. Any information would be helpful. It has not been drilled yet.

 

[GemGeek]

A photograph would be very helpful. Use your macro setting (little flower) if you have one and take it against a non-reflective white surface such as a paper towel. Thanks!