Autism Awareness Crystal Puzzle Piece Necklace. This dazzling puzzle piece crystal pendant hangs on an 18 inch serpentine chain that is made of 90% white copper and then coated with a pure silver plate. The chain is thinly nickel plated for adherence of the white gold plate. Lead free. The charm measures 1" across and a little over 1" high. It is bright and shiny and gorgeous! Add BLING to any outfit with this great necklace.