My Chase/Amazon credit card starting coming delaminated. It still worked okay but I was having trouble sometimes fitting it in the slots of card readers, so I reported it damaged and got a new card. The new one arrived yesterday, and it included a business reply envelop to send the old one back for safe destruction. I thought that was stupid; I'll just cut up the old card myself. The old card looked like it had a foil layer in it. Nope. The whole card was steel (probably stainless, but it was magnetic) with a plastic coating on the front. All the good stuff was on the back, embrossed in the steel. So I cut it up with tin snips and threw the pieces in the trash, but even that wasn't easy. That's why they sent the envelop.
I've never noticed such thing before. Today at the Chinese restaurant, the checkout girl dropped the card and when it went "clink" on the counter she commented how heavy it was.
ETA: actually, it was more of a "thunk" :)