Kautilya's Arthashastra 2.13.3

2.13.3

jāmbūnadaṃ śātakumbhaṃ hāṭakaṃ vaiṇavaṃ śṛṅgaśuktijaṃ jātarūpaṃ rasaviddham ākarodgataṃ ca suvarṇam //

Jámbúnada, that which is the product of the river, Jambu; Sátakumbha, that which is extracted from the mountain of Satakumba; Hátaka, that which is extracted from the mines known as Hátaka; Vainava, that which is the product of the mountain, Vénu; and Sringasúktija, that which is extracted from sringasúkti (?) are the varieties of gold.

(Gold may be obtained) either pure or amalgamated with mercury or silver or alloyed with other impurities as mine gold (ákaródgata).