Adamantine

Adamantine is a rare, high-value metal which is impossibly lightweight, strong, and sharp. Armor and edged weapons made from adamantine are absurdly valuable and wonderfully effective.

Description
Adamantine is a metal of impenetrable hardness and strength. It is often referred to with diamond features.

Applications
Adamantine has extreme material properties: it is nigh-weightless, extremely strong, and razor-sharp. These properties make it ideal for edged weapons and armor, but unfortunately, likewise make it near-useless for blunt weapons. Armor made of adamantine provides unmatched protection.

Because the metal's material properties are irrelevant in other applications and because it's so rare and hard to produce, using adamantine for other things is generally a waste. A single bolt can add hundreds of thousands of gold in value.

Trivia

 * Adamantine is originally from Greek mythology, wher Cronus castrated his father Uranus using a sickle of Adamantine given to him by his mother Gaia.
 * An adamantine sickle or sword was also used by the hero Perseus to decapitate the Gorgon Medusa while she slept.