It is a strong metal with the properties of earth and fire.
The metal is strong against water, wood, earth and lighting. Is weak to fire and really hot fire type elements or if you want to reword weakness, it is weak to any temperature varient element. Like super heated lightning or ice release because of it's coldness.
The metal is to be strong, very strong infact physically, like strong as diamond as it is neutral to that element. Any element that carries a strong physical trait is neutral with adamantine, except if it has less density then adamantine is stronger.
This is all i know