There had been some experiments with dynamic chains a while back, but needless to say I can't find the threads now.

As I remember it, they made a simple single sided ribbon with the links set along it. The links were set in the hard decorated group, so they followed the shape of the ribbon as it draped. The ribbon is made transparent for rendering, of course. For a very fine jewellery chain, you may even be able to get away with making your chain with displacement and transparency maps on the ribbon.