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Secret 6,500-Year-Old Copper Workshop Discovered

Workers digging in sand
Anat Rasiuk, Israel Antiquities Authority

Archeologists excavating in Beer Sheva, the largest city in southern Israel’s Negev Desert, have unearthed the remains of a copper-production workshop. The discovery sheds light on the meaning of metal in ancient civilization, the elevated position of craftsmen with the skill to free copper from rock, and the methods they used.

Tech Secrets

Most interestingly of all, the study, which was carried out by scientists from Tel Aviv University and the Israel Antiquities Authority, revealed that the copper that was smelted in Beer Sheva came from the area of Wadi Faynan, located over 62 miles to the east in present-day Jordan. Traditionally, ore-extraction facilities were found near the mines from which they came for efficiency purposes. In the Beer Sheva workshop, however, the researchers believe the distance might have served the function of protecting the secretive process.

“It’s important to understand that the refining of copper was the high-tech of that period,” said Erez Ben-Yosef, from Tel Aviv University. “There was no technology more sophisticated than that in the whole of the ancient world. Tossing lumps of ore into a fire will get you nowhere. You need certain knowledge for building special furnaces that can reach very high temperatures while maintaining low levels of oxygen.”

The copper-extraction process likely also blossomed in Beer Sheva due to the presence of water, which would have helped the craftsmen make the clay ovens and pots needed for smelting. And, the researchers found evidence that the process of removing the metal from surrounding rock was a two-stage process involving primary smelting in a furnace followed by refinement in crucibles. It’s the discovery of the clay furnace that most piqued the researchers’ interest.

Mobile Furnace

“At the first stage of humankind’s copper production, crucibles rather than furnaces were used,” said Ben-Yosef. “This small pottery vessel, which looks like a flower pot, is made of clay. It was a type of charcoal-based mobile furnace. Here, at the Neveh Noy workshop that the Israel Antiquities Authority uncovered, we show that the technology was based on real furnaces. This provides very early evidence for the use of furnaces in metallurgy, and it raises the possibility that the furnace was invented in this region.”

Bits of rust-colored rock on a sheet
Excavated bits of copper slag, the remnants from the smelting process. Anat Rasiuk, Israel Antiquities Authority

The researchers also believe that one-time residents of the Beer Sheva region—members of the Ghassulian culture—traded for the ore with people living near the mine rather than hauling the rock themselves. The Ghassulian craftsmen would then smelt the copper in workshops manned by elite members of the society.

Through chemical analysis of remnants in the region, the researchers found that each workshop had a particular, closely guarded recipe that wasn’t shared.

“At the beginning of the metallurgical revolution, the secret of metalworking was kept by guilds of experts,” said Ben-Yosef.

The researchers add that their discovery points to a highly stratified society where skilled craftsmen held the highest positions thanks to keeping their technological secrets safe.

Technological Powerhouse

Although metallurgy was being practiced in this region 6,500 years ago, the researchers point out that the items created from the copper were symbolic or ceremonial; stone was still the primary source for serious tools.

Although Ben-Yosef believes that Beer Sheva could well be the first place on Earth where the smelting furnace was used, he also admits that it might have been imported from elsewhere.

“It’s also possible that the furnace was invented elsewhere, directly from crucible-based metallurgy, because some scientists view early furnaces as no more than large crucibles buried in the ground,” Ben-Yosef he said. “The debate will only be settled by future discoveries, but there is no doubt that ancient Beer Sheva played an important role in advancing the global metal revolution and that in the fifth millennium BCE the city was a technological powerhouse for this whole region.”

The research has been published in the peer-reviewed Journal of Archaeological Science: Reports.