Anandakanda 2.1.161

2.1.161

kṣiptvātape puṭe pacyātpratyekena punaḥ punaḥ /
evaṃ niścandrakaṃ vyoma kajjalābhaṃ mṛtaṃ bhavet //

Having placed it in the sun, one should cook it in a calcination with each one repeatedly. / In this way the mica becomes lustreless, resembling collyrium, and killed.