This is a small copper axe, found as a single find in Kassel-Kirchditmold during the 1930ies. It may roughly be dated between 3.0-2.0 k.a. BC. The artefact was certainly not used for utilitarian purposes.
Copper occurs naturally as native copper or as part of minerals such as Malachite (CuCO3Cu(OH)2) or Azurite (2CuCO2Cu(OH). A major innovation in Prehistory was the application of advanced levels of pyrotechnology on copper minerals, during the early Neolithic of the Middle East.
Pyrotechnology seems to be rooted in the PPNB of the Levant. Here this technique was used in the production of lime plaster for architectural and other purposes. One example is the mid-PPNB site of Kfar Hahoresh, Radiocarbon dated to 8,5-6,7 k.a. calBC. The quantity of material used at Kfar Hahoresh and other contemporary sites and the temperature necessary for limestone calcination imply that some sort of crude kilns must have been used.
The earliest use of ore (malachite) in the production of small nun-utilitarian objects began by about 9 k.a. BC. Such objects were uncovered from PPNB strata at Hallan Çemi and Çayönü. At 8 k.a. BC, the inhabitants of Aşıklı Höyük near Aksaray and Çayönü near Diyarbakir, collected native copper and worked it to produce small tools and ornaments like beads. The metallurgical evaluation of these metal objects showed that early metal smiths were shaping native copper into sheets by hammering and repeated annealing, that is re-heating to avoid cracking.
The earliest evidence for copper smelting, now questioned, is from Çatal Höyük IX. A small quantity of melting slag from the mid-seventh millennium is thought by some scholars to prove the onset of an extractive metallurgy. It has to be noted, that other causes for the formation of the “slug” are possible. From a chemical point of view it could be simply weathered native copper.
Copper smelting is known to have occurred shortly after 5 k.a. BC in Anatolia. At Yümük Tepe cast copper axes and chisels were found in a secure context. Some of these show chemical compositions which strongly suggest a production by smelting. A similar age is claimed for some sites in Iran.
Recent discoveries showed that extractive copper technology may have been invented in separate parts of Asia and Europe rather than spreading from a single source. In 2007 excavations at Pločnik, a Vinča Neolithic site in Serbia revealed a copper chisel casting which is older than the one at Yümük Tepe, dating to a period just after 5500 BC. Finds and situations encountered at other Vinča sites in Serbia (Vinča, Pločnik, Belovode, Fafos) support early extractive metallurgy in the central Balkans to the very beginning of the Vinča culture (http://www.aggsbach.de/2011/06/vinca/).
In the Near East and in South-East Europe extractive Copper technologies had a major impact on certain Neolithic societies as described by B.S. Ottaway (http://www.ffzg.hr/arheo/ska/tekstovi/copper_metallurgy.pdf), while the influence of metallurgy to central and west Europe societies was more limited until the beginning of the Bronze Age. This is also the reason, why the “Chalcolithic” period does not play a prominent role in the periodisation of the Neolithic of these countries.