Rasendracudamani 10.42

10.42

{abhra:: sattva:: pātana:: separating kiṭṭa and sattva}
koṣṭhyāḥ kiṭṭaṃ samāhṛtya vicūrṇya ravakān haret /
tatkiṭṭaṃ svalpaṭaṅkena gomayena vimardayet //

Mica: metallic essence: extraction: separating slag and metallic essence:
Collecting the slag from the furnace and crushing it, one should take the grains. / That slag one should grind with a little borax and cow dung;