Trials upon heated air in France

Abstract

The first known use of metals in the Southern Levant is during the Chalcolithic period (end of fifth to most of the fourth millennium BC). Dating from that time more than 500 metal objects have been found mainly in hoards, burials, and habitation remains, most of the metals come from sites in the southern part of Israel and Jordan and very rarely from beyond the center of Israel and north of Nahal Qanah. Most of the metals belong to two major categories and there is also a third, minor category:1.Prestige/cult elaborated and complex-shaped objects made of copper (Cu) alloyed (either by a deliberate choice of complex minerals or by adding several minerals together) with distinct amount of antimony (Sb) or nickel(Ni) and arsenic(As). They were cast in a ‘lost wax’ technique into single closed clay molds and then polished into their final shining gray or gold like colors depending on the amount of antimony or nickel and arsenic in the copper. The biggest hoard (416 metal objects) comprising mainly of these highly artistically complex-shaped objects was found hidden in a remote cave (the cave of the treasure) in Nahal Mishmar, Judean desert, Israel, wrapped in a straw mat. The origin of the complex source material for the production of these objects is currently unknown. The nearest suitable ore is in Trans Caucasus and Azerbaijan – more then 1500 km from the finding sites of the objects. Several clay and stone cores and clay mold's remains were petrographically analyzed and the results point to a possible local production within the metals distribution zone in Israel. Currently, no production remains or production sites of these prestige/cult objects have been found.2.Unalloyed copper tools comprising mainly of relatively thick and short bladed objects (axes, adzes, and chisels) and points (awls and/or drills) made from a smelted copper ore cast into an open mold and then hammered and annealed into their final shape and their blade's or point's hardness properties. The copper tools were produced in the Chalcolithic villages on the banks of the Beer-Sheva valley where slag fragments, clay crucibles, some possible furnace lining pieces, copper prills and amorphous lumps were found beside high-grade carbonated copper ore (cuprit). The ore was collected and selected in the area of Feinan in Trans-Jordan and transported to the Northern Negev villages some 150 km to the north to be smelted there for the local production of these copper objects.3.A group of eight gold (Au) and electrum (Au + up to 30% Ag) solid rings was found in Nahal Qanah cave. This unique find, with no dated parallels, is attributed by the excavators to the Chalcolithic period based upon local stratigraphic and geological reasons and 14C dating of ground samples from the vicinity of the find in the cave. Surface analyses of these objects revealed a surface gold enrichment caused by the depletion of silver and the copper traces. This effect could be caused naturally by deposition, but could as well result artificially at the time of production in order to achieve a yellow color for the electrum rings rich in silver. During the Chalcolithic (copper + stone) era at least two, if not three different metal industries of different metals beside copper were operating and left their products in the Southern Levant.