Anandakanda 2.8.53

2.8.53

kṛtādiṣu yugeṣvetau vajrāṇāmākarau smṛtau /
ākareṣveva vajrāṇāṃ khaniḥ srotaḥ prakīrṇakam //

in the ages beginning with Kṛta, these are remembered as the sources of diamonds. / Regarding diamond sources themselves, a pit-mine, a riverbed, and surface-deposit: [these three]