Marcasite & Black Stone Necklace

Beautiful art deco period marcasite and black stone necklace. The stone is likely to be obsidian but potentially black glass. In an wonderfully elegant design and in excellent condition. One stone is missing as photographed but very difficult to tell unless closely inspected. A wonderful and original art deco piece of jewellery with a secure clasp. The main pendant part measures 5.5 x 3.5 cms.