Rasarnava 4.49

4.49

āvartamāne kanake pītā tāre sitā prabhā
śulve nīlanibhā tīkṣṇe kṛṣṇavarṇā sureśvari //

When gold is being melted, the luster is yellow; in silver, white;
in copper, it resembles dark blue; in wrought iron, black-colored, O mistress of the gods;