EASTON’S BIBLE DICTIONARY (1897 EDITION)
Adamant – (Heb. shamir), Ezek. 3:9.
The Greek word adamas means diamond.
This stone is not referred to, but corundum or some kind of hard steel.
It is an emblem of firmness in resisting adversaries of the truth (Zech. 7:12), and of hard-heartedness against the truth (Jer. 17:1).