Kautilya's Arthashastra 2.14.5

2.14.5

yathāvarṇapramāṇaṃ nikṣepaṃ gṛhṇīyus tathāvidham evārpayeyuḥ //

(The goldsmith of the mint) shall return (to the owners coins or ornaments) of the same weight, and of the same quality (varna) as that of the bullion (nikshepa) which they received (at the mint). With the exception of those (coins) which have been worn out or which have undergone diminution (kshínaparisírna), they shall receive the same coins (back into the mint) even after the lapse of a number of years.