The 6,000-year-old artifact –discovered at the Neolithic village of Mehrangarh, Pakistan– was created with a technique still used by NASA. As researchers explain: “It is also today the highest precision metal forming technique—under the name ‘investment casting’—in aerospace, aeronautics, and biomedicine, for high-performance alloys from steel to titanium.”
Researchers have recently come across a 6,000-year-old ornament excavated at the Neolithic village of Mehrangarh, Pakistan. According to a new imaging technique that allowed researchers to find out more about it, the artifact was created with an ancient technology that NASA still uses today reports Mail Online.
The technology called lost-wax casting is a metal casting technique still used today in order to create a duplicate metal object. A modern version of the method called ‘investment casting’ was utilized by researchers at NASA when they built components for the International Space Station, the Curiosity rover exploring the red planet, and other spacecraft like the Messenger probe.
(a) Map indicating the major Indo-Iranian archaeological sites dated from the seventh to the second millennia BC. Scale bar, 200 km. (b) View of the MR2 archaeological site at Mehrgarh (sector X, Early Chalcolithic, end of period III, 4,500–3,600 BC). (c) View of the front side of the wheel-shaped amulet. Scale bar, 5 mm. (d) Dark-field image of the equatorial section of the amulet.
The 6,000-year-old ornament was studied using a revolutionary new technique called ‘photoluminescence imaging’ by scientists from Ipanema – a European research facility that specializes in the study of archaeological materials.
The new technique allowed experts to determine the exact process by which the artifact was made in the past.
“We discovered a hidden structure that is a signature of the original object, how it was made,” stated lead author Mathieu Thoury, a physicist at Ipanema, the European center for the study of ancient materials, as quoted by the Washington Post.
“You have a signature of what was happening 6,000 years ago,” Thoury added.
‘Photoluminescence imaging’ is a process where light is being projected onto the artifact while researchers measure the amount of light that bounces back.
Scientists explain that different material consequently reflects different amounts of light, which in turn allowed experts to pinpoint the exact materials used in the production of the ornament some 6,000 years ago.
After studying the artefact in detail, experts concluded that the amulet was in fact created as a single piece which led experts to conclude that whoever created the ornament used a process called lost-wax casting.
Lost-Wax Casting involves in the production of a ‘replica’ item using wax, and then creating a mold around the object. When it’s heated up, the liquefied wax is removed, and molten metal is poured in. Once the mold cools down it is broken apart which leaves only the newly formed metal inside it.
Experts discovered that the ancient craftsman created the amulet by pouring –extremely pure— copper melt into a mold that was previously created using lost-wax casting. The study was published in the journal Nature.
Ivan is a freelance writer, editor-in-chief of ancient-code.com, he also writes for EWAO, Share Knowledge, Svemir Online and Ancient Origins.
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