Anandakanda 1.9.68

1.9.68

hemābhrakāntabhajanād yogyaḥ syādvajrabhakṣaṇe /
<vajrarasāyanam>
pūrvavadbhasmayed vajraṃ dhātrīnīreṇa mardayet //

From the consumption of gold, mica, and loadstone, he becomes qualified to eat diamond.
<Diamond Rejuvenation>
One should reduce diamond to ash as before, and grind it with juice of āmalakī.