Absolutely, positively DO NOT GIVE YOUR CARD INFORMATION TO THAT SELLER IF THAT SELLER IS NOT A DEALER.
Think it through.... What is that seller going to do with that card info since he isn't a dealer? He has no way to process the card or get paid for the transaction. What to stop that individual, or group, or criminal organization go on a shopping spree at an online jewelry store for things they can easily fence. They just camp out in front of your home and pick up the orders. You won't know until you get your credit card bill.
(Disclosure: I worked for one of the two major credit card organizations for over 20 years, mostly in the security and risk division.)
Think it through.... What is that seller going to do with that card info since he isn't a dealer? He has no way to process the card or get paid for the transaction. What to stop that individual, or group, or criminal organization go on a shopping spree at an online jewelry store for things they can easily fence. They just camp out in front of your home and pick up the orders. You won't know until you get your credit card bill.
(Disclosure: I worked for one of the two major credit card organizations for over 20 years, mostly in the security and risk division.)