This is one of the Djinns that are named after the jewels Ruby, Sapphire, and Diamond. As high level shield-using Paragons, they have fairly high armor. They are vulnerable to Earth damage, and have no specific resistance to the other types of elemental damage, although it's possible that they do have a slight Fire damage resistance.
The Diamond of Ahdashim is a special version of Diamond Djinn found in the Dasha Vestibule that drops a Diamond Key. It is otherwise exactly the same as a regular Diamond Djinn.
Bug! These creatures appear to have the benefits of being a boss, including halved skill activation time, double damage and natural health regeneration.
