Anandakanda 1.6.121

1.6.121

śulbajīrṇo raktavedhī kāntajīrṇo rasātmakaḥ /
tīkṣṇabaddhena nīlābhas tāmreṇāruṇasaprabhaḥ //

Consumed copper, it transmutes blood; consumed loadstone, it transmutes bodily fluid. / Bound with steel, it has a dark blue lustre; with copper, it has a reddish glow;