Anandakanda 2.8.50

2.8.50

śyāmaṃ prapauṇḍraprabhavaṃ kiṃcit pītaṃ mataṅgagirijātam /
himavatsurāṣṭrasaṃbhavam ātāmraṃ kṛṣṇakānti saupāram //

Darkish is that originating from Prapauṇḍra; slightly yellow is born from Mount Mataṅga; / coppery comes from the Himālayas and Saurāṣṭra; black in luster is from Saupāra;