Researchers meeting to analyse the Mehrgarh amulet

Researchers meeting to analyse the Mehrgarh amulet in the Disco beamline UV/visible synchrotron photoluminescence microscopy room at the SOLEIL synchrotron light source centre. A beamline serves to extract photons, select their energy range and focus the synchrotron beam on the subject. The Disco microscope, which covers the VUV-visible range from 180 to 1,000 nm, was used to analyse this copper amulet from the Chalcolithic period, discovered at Mehrgarh in present-day Pakistan. This analysis enabled us to work out how it was made. This amulet is the oldest known object made by the lost wax process, which uses a model sculpted in a material like beeswax that is subsequently encased in a clay mould. Because wax melts at low temperature it runs out easily when the clay is heated. Molten metal is then poured into the clay mould, filling the empty space left by the lost wax.