In 1961, an extraordinary treasure was found in a cave near the Dead Sea known as Nahal Mishmar.
Hidden in a natural crevice and wrapped in a straw mat, the hoard contained 442 different objects: 429 of copper, six of hematite, one of stone, five of hippopotamus ivory, and one of elephant ivory. Many of the copper objects in the hoard were made using the lost-wax process, the earliest known use of this complex technique. For tools, nearly pure copper of the kind found at the mines at Timna in the Sinai Peninsula was used. However, the more elaborate objects were made with a copper containing a high percentage of arsenic (4–12%), which is harder than pure copper and more easily cast.Radiocarbon dating showed that they were from the Chalcolithic or Copper Age, between 4000 and 3500 BC.