Triple Moon Necklace by St Justin of Penzance £30.00 New stock arriving soon. Triple Moon Necklace A pewter triple moon design necklace with a rainbow moonstone cabochon on 18″ tin-plated curb chain. Width: 59mm Height: 28mm | Overall length: 18 inch (45cm) Supplied in a satin and velvet-lined gift box. The venerable alloy of pewter is made of 92% tin, with copper and antimony to harden it and enhance casting. All of our St Justin Pewter products are LEAD FREE.