Victorian Pinchbeck, Amethyst And Paste Snake Necklace Circa 1890 Highly desirable pinchbeck snake necklace studded with foiled paste 'diamonds' and with real amethyst eyes and headstone. Beautiful snake link chain, a gorgeous and more affordable version of the gold snake necklace Pinchbeck is a form of brass, an alloy of copper and zinc, mixed in proportions so that it closely resembles gold in appearance. It was invented in the 18th century by Christopher Pinchbeck, a London clockmaker. Since gold was only sold in 18-carat quality at that time, the development of pinchbeck allowed ordinary people to buy gold 'effect' jewellery on a budget.It has now become a very collectible and desirable metal especially because unlike gold plate it is solid and so never wears away. measures - …. wearable length laid flat (sits perfectly around the collar bone)