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Medieval Africans had a unique process for purifying gold with glass (2019)
And scientists in Illinois have recreated it.
When Sam Nixon, an archaeologist with the British Museum, excavated ancient coin molds in Tadmekka, Mali, in 2005, it triggered a several-year exploration of how medieval Africans purified the gold they were using for their currency. Tadmekka was a town right in the middle of the trans-Saharan caravan route, so Nixon uncovered several types of material culture that had to do with trade, namely molds for “bald dinar,” or coins that hadn’t been stamped with the name of a mint (or a 10th-century equivalent of one). Though Walton and his team updated this small-scale, bespoke process for purifying gold to modern times and adapted it to their environment in Illinois, their results show that the medieval Malian technique was both clever and sophisticated.
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