Despite its abyssal nature, Darkglass is actually most effective against the Others. Their usual protection and resistance from Magic does nothing to save them from this material, making it an extremely effective tool for the sorcerers that fight against them.
Darkglass, despite the fact that its chemical composition is far from that of silver, can imitate its debilitating and poisonous properties when used against the Lucareth. Likewise, against the Sidhe it takes on the consistency and damaging property of coldforged iron. When it cuts or touches other Fae however, the material remains obsidian.