Silver and Gold Coins
It has been suggested that the Indians in Peninsular India did not know the
use of silver and gold cur- rency, and that, for the most part, the imported
coins can only have been used as bullion. But we have some silver coins
ascribable to the Satavahanas, and the epigraphic evidence suggests the use
of silver pana. Hence Roman gold coins may have been valued for their
intrinsic worth, but may also have been circulated in big transactions.
    In the north-west, the Indo-Greek rulers issued a few gold coins, but the
Kushanas issued them in considerable numbers. It is difficult to subscribe to
the theory that all Kushana gold coins were minted out of Roman gold. As
early as the fifth century BC the Indian satrapy paid a tribute of 320 talents of
gold annually to the Persian empire. The source of the metal may have been
the gold mines, reported to have existed in Sind in the time of Alexander.
This territory and probably the gold mines of Dhalbhum lay under the sway
of the Kushanas, who enjoyed the benefit of the knowledge of melting and
mining transmitted by the Mauryas. But on account of contact with Rome
they began to issue the dinara type of gold coins, which became abundant
under the Gupta rule.
Leas and Copper Coins
In day-to-day transactions, however, silver and especially gold coins could
hardly be used by the people. Patanjali refers to payment in nishkas to the
wage earners (karmakaras), but these do not seem to have been gold coins at
this stage. In this connection the issue of lead or potin* coins by the
Satavahanas is significant, for it indicates that in the Deccan and in the
coastal areas money economy had come to be prevalent.
    The same inference can be drawn in respect of northern and north-
western India from the coinage of the Kushanas, who perhaps issued the
largest number of copper coins. Copper coins were also issued in large
quantities by the Naga rulers, espe- cially Ganapati Naga, and by several
indigenous dynasties such as those of the Yaudheyas and the Mitra rulers of