Over 10 000 years ago, peoples around the Mediterranean basin were hammering unheated rock rich in pretty green copper ore and making objects with it: beads, pendants and other small ornaments. After thousands of years of hammering, people began heating tiny amounts of copper ore in small clay pots called crucibles, producing metal. Now, Israeli archaeologists report on evidence of the next stage: a furnace smelting, dating to about 6 500 years ago in Be’er Sheva, using ore imported from Wadi Faynan in Jordan, more than 100 kilometres distant.
The discovery of fragments of furnaces, crucibles and slag from a big copper smelting workshop at the Horvat Beter archaeological site was reported by Prof. Erez Ben-Yosef, Dana Ackerfeld, Omri Yagel of Tel Aviv University, Dr. Yehudit Harlavan of the Geological Survey of Israel and Talia Abulafia, Dmitry Yegorov and Yael Abadi-Reiss of the Israel Antiquities Authority and colleagues in the Journal of Archaeological Science.
The team isn’t asserting that furnace smelting was invented in the Be’er Sheva Valley or even the southern Levant, but that their find, a fixed (immovable) furnace made of clay built into the ground, is one of the earliest of its kind. Others from the era have also been found in the Be’er Sheva area. The workshop employed a sophisticated two-stage process: Furnace-based primary smelting of the rock, followed by further melting or refining of the metal in crucibles.
The primal technique of crucible smelting involved putting bits of copper ore into a small clay pot, adding charcoal, and igniting it to melt the copper out of the rock. The pot wasn’t covered. The embryonic metallurgist would blow air into it to raise the temperature, Ben-Yosef explains: “It was a kind of very small portable furnace.” The earliest evidence of crucible smelting was found in Anatolia and Iran, dating to the late sixth millennium B.C.E.