Anyone ever sell gold/diamonds?

Anyone ever sell gold/diamonds?

I came across my old wedding set in a box. (Old as in from my previous and unlamented marriage.) It's not a huge thing- a slim gold band and a solitaire engagement ring with a 1/2 carat diamond. Has anyone here successfully turned such items into cash? Any recommendations of companies to try or to be wary of or tips on how to go about selling would be much appreciated. I know there are places that will send you a mailer to send your stuff to them but I'm hesitant to just mail off a diamond to a company with no references.
Photos and a question

Photos and a question

Black Forest Cake

Black Forest Cake

Plant ID please!

Plant ID please!

IDs, please

IDs, please

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Studio Vs. One Bedroom

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Ikea is tiring and a lamp question