Magical Material and Artifacts

Artifacts
Even though it has been forgotten Ethereal exalted do have a magical material that is aligned to them. A long forgotten material named Adamant. It does exist in know creation but no one has been able to reproduce it or work into any useful shape.
Adamant is diamond hard glass made from melted ground (rock, sand, et) after a lighting strike from Azure. This material is called Fulgurite. Fulgurite is then processed through a alchemical means only known to the Ancient Solars, Ethereals and other's that lived before the Primoridal War. When Azure was "expelled" the process was lost but his children may remember the process as their madness subsides

When used in melee weapons, Adamant inflicts piercing damage and reduces the soak of the target's armor by 4 after soak is halved for piercing damage. When used in armor, Adamant increased the lethal soak by 3 and reduces the Fatigue value by 1. In ranged weapons, Adamant causes Piercing damage just as it does in melee weapons.

A ethereal can stay attuned to Adamant regardless of the cast they are using.

Other Magical Materials
Changeling can attune to other magical materials by paying double the cost as other Exalts do or if they have a cast that corresponds to the metal, they attune while they have the cast active and gain all the benefits that an aligned Exalt would get. When the Ethereal changes castes they lose the attunement.