sorry, this page is nothing other than a #lunamerchantinspo picture...
but I guess while you're here I can tell you my number 1 recommended tool for jewelry buying and assessing: the jeweler's loupe. I never leave home without it and I'll never buy a piece of jewelry without looking at it under magnification. You shouldn't either! The link below has two options from Amazon. I personally own the Zeiss loupe, but feel free to start out and practice with a less expensive version. Just know, when it comes to buying pricey items like jewelry, the better quality tool, the better quality view!