92.5% Silver, i.e Sterling Silver.
Gold is measured in "karats". Pure gold is 24K. So, testing your math skills (where's that calculator), what is the percentage of gold in the average 14k jewelry they sell in the US?
Hint: Not very much.
Is it any wonder that most Asian and Middle Eastern countries offer 21 and 22k gold? It's a far better value.
Back to your question: Diamonds are measured in a different "karat", but also graded by several factors, the four "C"s as they are called: Cut, Color, Clarity and Carat Weight.
As valuable diamonds are rarely set in silver, and even moderately large diamonds with poor specs under the 4 C's are not expensive, I can estimate that this ring, not even seeing it, is not worth more than $150, and possibly much less.