I found a ring about a year and a half ago that tested as diamonds
Took it to a jewelry store where I have spent some dollars and young lady tested it and said Its Real and a very nice diamond.
Happened to be in a jewelry store in November to get the battery in my watch changed and the lady said "My Husband detects" so I took the time to show her a couple of my finds.
The Jeweler said Can I look at your ring? He tested it and it showed that it was a diamond. He then tested it for moissanite and the test was positive. The ring is marked 14k and according to his test it has man made stones
The main stone if it was a diamond would be at least 1 carat so sometimes junk does get put in gold rings.
Just my 2 cents but DO NOT sell it to the jeweler. He's looking to buy wholesale from you and he'll turn around and sell that $550 ring for 2K minimum.
Jewelry markup is typically 400% give or take.
Get it appraised (Say 2K for argument's sake) and put it on Ebay or something for $1,000 and turn a better profit.
Just my two cents from having bought an engagement ring once and then having the store I bought it at offer me $1,000 (when the engagement ended, that you God) on the ring they sold to me for $4000. I sold it myself for $2500!