I am sorry but I do not know what the chain is made of and there are no markings. I would say that it is made of an aluminum alloy or nickle because there is not much weight to it. The heaviest things about the necklace are the stone beads.
I understand. I recently discovered that I have an aversion to nickle as well. I'm going to be posting a lot of my old jewelry up here as a result. lol And just some jewelry to get rid of to make room for new pieces. :D