Iridium Armour significantly increases the resilience of the Battlesuit's external armour to the point where it can shrug off all but the heaviest firepower.
This enhanced protection comes at the cost of a decrease in manoeuvrability due to the armour's increased weight impeding the function of the Battlesuit's Jetpack.
Iridium Armour is an upgrade only available to Battlesuit pilots of the rank of Shas'vre or higher, and its rarity means that its distribution is usually limited to only one per Hunter Cadre. However, further refinements of the upgrade's technologies resulted in the development of the XV89 Crisis Battlesuit variant that was specifically designed to be fitted with Iridium Armour.
However, inherent weight problems in its design caused production to slow, and eventually the prototype XV8-02 Crisis "Iridium" Battlesuit was developed. With this new variant of the XV8 Crisis Battlesuit, Iridium Armour is no longer an available Battlesuit upgrade.
- Codex: Tau Empire (4th Edition), pg. 26
- Codex: Tau Empire (6th Edition), pg. 73
- Imperial Armour Volume Three – The Taros Campaign, pg. 174