To not refund this eBay buyer?

[GruffaIo]

I sold an expensive ring back nearly two months' ago. It was delivered and signed for. Today the buyer has contacted me to say that, in a certain light, they can see a crack in the stone. It was used but there were absolutely no cracks. I have photos online, but they don't show every angle. I've asked the buyer for photos. But I'm thinking I shouldn't refund anyway as they have had the ring for nearly two months. Anything could have happened to it in that time. AIBU to not offer to refund? The buyer hasn't asked yet, but that must be where they're going with this. If I don't offer to refund, will eBay try and force me, even though they've had it for so long?

As you have legal knowledge OP I hope it goes well for you, it bodes well. I had a bad experience with an ebay buyer. She was definitely dishonest but ebay took her side. I did get the item back but she was clearly a liar. All I could do was block her so I'll never have to deal with her again!

So many people have clicked on to eBay usually taking the buyers side.
I had one person who bought a pair of very expensive shoes from me (she paid maybe 1/8th of RRP and they'd only been worn for my wedding ceremony because they'd crippled me), I packaged them, sent them to her and a month later she informed me there was a patch missing glitter and demanded a refund. I offered to refund her on return of the items, she said this wasn't an option for her but she wouldn't be leaving me feedback. She'd basically wanted a refund and to keep the items - which I later saw relisted for a much higher price so she'd have really cashed in. Not on my watch!!!
Hope you get it sorted OP.

The buyer opened an eBay dispute today, which was promptly closed in my favour when I declined to refund. She has now opened a Paypal dispute, which I have escalated to get a formal decision. I am providing all the supporting evidence I've got. I'm really disappointed though I suppose it wasn't unexpected.