Brihadyogatarangini 61.63

Bṛhadyogataraṅgiṇī 61.63

yatrāṅgaṃ dṛśyate lauhe tīkṣṇaṃ lohaṃ taduttamam
kāsīsāmelakalkākte lohe'ṅgaṃ dṛśyate sukham