The topaz is in dire need of cleaning but since I didn't have the proper cleaning products, I just wiped it off with a damp rag.
I think it's a blue topaz but I'm not 100% positive. It tested as a gemstone on my meter (see photos).
The ring is size 7-1/4 and the ring weighs 3.6 grams
It is marked inside with "10K" as well as "WM"
Thank you so much for looking!