On the Composition and Processing of Precious Metals Mined in Medieval Serbia

Abstract

Accounting books of the Caboga (Kabužić) brothers 1426-1433 (Squarço/Reminder, Journal and Main Ledger) kept at the Historical Archives of Dubrovnik provide new evidence for the composition and advanced levels of processing of precious metals from Serbian medieval mines. Notably, that the residue left after the process of obtaining fine silver was copper. Even the price of the refining process is specified. Two items of a transaction entered in the Squarço in 1430 contain some previously unknown data about auriferous silver (argento di glama). Besides gold, it also contained copper and, moreover, the ratio of the two per pound is specified. Apart from the Caboga brothers’ accounting books, neither the other written sources nor geological research have provided any indication about the presence of copper in the auriferous silver mines.