I find it so hard to determine if they're legit or not. If they say something is, e.g., a garnet or gold how do I know if it is true? I feel like jewellery is an area where it's easy to be sold a pup, perhaps that is an outdated view. A random page from a site I'm looking at: https://www.thbaker.co.uk/second-hand-vintage-9ct-yellow-gold-opal-emerald-cluster-ring-41102536 how would I begin to evaluate such a listing?