Can't you get one locally? Which country do you live in? You will only find scammers here.
In France. No local merchant accepts payment in crypto in the surrounding area, moreover they risk asking for proof :-(.
Bitdials = KYC requirement I do not want to do KYC. Here is what I am looking for approximately: https://www.bitdials.eu/products/buy-original-certified-gia-diamond-2-01-1133689676-with-bitcoin-btc-monero-xmr-ether-eth-crypto-coins
with certificate of authenticity
Afterwards I can always buy on different forms of purity and grade color
For the ruby a beautiful one of about 1.50 carats (Pigeon blood) I also accept in other forms.
I saw that it's hard today to find someone to trust.