Some other angles:
Second day out yesterday in South Africa and first gold ring. Art Nouveau style 18k yellow gold ring with what I estimate to be a 3/4 carat diamond of excellent color and clarity, with 2 smaller accent diamonds. Found under waist deep sea, wedged in a rock crevasse. Wacky vine/floral design art piece suggests it is probably a few decades old. It looks like a different ring from every angle.
I will take it into to my gold buyer/jeweler here on Monday to get an appraisal and then sell it locally. I suspect book value will be in the $3000-$5000 range. Perhaps $4000. Let's see how accurate I am...