Hi,
This is Oscar Morante from Portland Gold Buyers, LLC in Portland Oregon. I buy a lot of jewelry for refining. Here is my answer.
It is very unusual for diamonds to be set in silver. The reason is evident. The quality of the stone is associated with the quality of the metal. Thus, the better stones will be in 18K or 14K gold or in Platinum. 10K gold is usually associated with smaller and lower quality diamonds. Silver is usually associated with inexpensive stones or "diamond simulants" ( a nice way of saying fake diamond).
If you have any questions contact me at sell@portlandgoldbuyers.com. Below is a good video of a diamond acquisition I made some time ago.