Antique pearl brooch

[Billgem]

I have an interesting pearl brooch in for appraisal. Before sending to GIA, I would like some input, if possible. The pearl measures approx. 22 x 21 mm. in diameter and approx. 14 to 16 mm. deep. The color is similar to a white/silver south sea pearl. The surface is smooth with just a few blemishes. The surrounding diamonds measure approx. 7.5 mm. each. I estimate the age around 1900. I am hoping someone might be able to tell me something of the type of pearl this is?
Thanks,
Billgem, Sorry unable to attach pictures at this time (problems with the system?)

 

[Billgem]

Thanks

Thanks

I have tried to attach pictures, but with no success. I guess I am too new to understand the proceedure. If you are interested, I would be glad to send pictures using regular email.
Bill