Mabe pearl 18kt Yellow Gold Ring, diamonds, estate Ring vintage

smoke-free home. has six small diamonds around the outside that add up to .12 carat total weight. set an 18 karat yellow gold. this is an estate ring. I took it to My jeweler and he did not see a stamp on it so he tested it and it tested 18 karat yellow gold. this was my grandmother's. she's been gone 20 years and she probably had this 50 years. can be resized but it has a double band, according to my local jeweler. size is currently 5.25. please see photo. please buy with confidence as Posh authenticates anything over $500. just thinning out my jewelry a bit.