Iridium(III) chloride hydrate is used to prepare other iridium compounds. It finds use as a catalyst for oxidation in presence of cerium(IV) and in the the manufacture of electrodes. Iridium(III) chloride is used in iridium electroplating, in making the standard meter bar of Paris and crucibles. It is used for high temperature electrical contacts, as hardening agent, in tipping pens and compass bearings and Pt/Ir spark plugs. It is used for medical, surgical or other patient oriented applications, MMO (mixed metal oxide) titanium electrode coatings and as a starting material for heterogeneous catalysts.