Diamond

From the ancient Greek word "Adamantinos" (meant "of the diamond"), of the ancient Greek word "Adamas". The word Adamas is a combination of the word "A" which meant "none" or "not" in ancient Greek, and the root word "Dam-", which meant "to tame". So "A-damas" actually meant "the untameable" in ancient Greek. Thats the name they gave to the precious stone (diamond) because of its toughness.