Anandakanda 2.8.135

2.8.135

amlabhāṇḍagataṃ secyaṃ saptāhād dravatāṃ vrajet /
bhasmaudanaṃ drutiśceti trividhaṃ vajramāraṇam //

and placed it in a vessel of sour gruel, sprinkled with it, it liquefies in seven days. / Calx, mush, and liquefied diamond—thus threefold is diamond killing;