(קַלְקַנְתּוּם, קַלְקַנְתּוֹס, קַנְ׳ m. (κάλκανθος, calcanthum) vitriol(also called atramentum sutorum, v. Sm. Ant. s. v.), used as an ingredient of shoe-black, and of ink. Gitt. II, 3 ובקנ׳ and with calcanthum (as writing ink); expl. ib. 19ᵃ חרתא דאושכפי, v. אוּשְׁכָּפָא. Erub. 13ᵃ דבר אחד … וק׳ שמו וכ׳ I have an ingredient whose name is calcanthum, which I put into the ink. Tosef. Sabb. XI (XII), 18 אחד נותן את הדיו … הק׳ if one puts in the (dry) ink, another the water, and a third person the calcanthum; a. e.