это-то меня и смутило 
вполне серьезные специалист по индийской антике Rekha Jain в своей книге Ancient Indian Coinage описывая теории происхождения индийских клейменых монет указывает на версию вавилонского поисхождения
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James Kennedy thought that the punch-marked coins, which formed the most ancient currency of India, were copied from Babylonian originals after the opening of the maritime trade with Western Asia in the sixth century вс. He argued on the basis of the similarities between Indian punch-marked coins and Babylonian punched-coins called shekels. Both are punched and bear no inscriptions on bust of kings or divinities. Both are flat and similar in shape. Both had standard weights but no standardize. Both used a small copper alloy. The jatakas show how Indian merchants used to go to Babylon for trade, and it is almost certain that India imported her supply of silver from that quarter in the form of spread-out plates, which determined the size of punch-marked coins.
часто встречается сигл 
