Anandakanda 1.10.25

1.10.25

evaṃvidhaṃ sūtarājaṃ kāntabījaṃ dvayaṃ samam /
mardayettaptakhalve ca sāmlavarge dinatrayam //

With such a king of quicksilver and the magnetic iron seed—the two in equal parts—
one should grind in a heated mortar with the group of acids for three days.