The shamir – Ask the Rabbi

A. In the Tanach (Isa. 5:6, Jer. 17:1) it is a sharp substance, a thorn or a diamond.
Tradition regarded the shamir as a miraculous worm which could split any hard stone or metal by merely crawling across it. As this is quite out of the ordinary, Pirkei Avot lists it amongst the miraculous things created just before the first Shabbat.
It was used to hew stones for the Temple as iron, the symbol of weapons of war, could not be used (Ex. 20:22).

