Yttrium aluminium garnet (Ce:YAG) is used as a phosphor in cathode ray tubes and white light-emitting diodes, and as a scintillator. YAG for a period was used in jewelry as a diamond and other gemstone simulant. Colored variants and their doping elements include: green (chromium), blue (cobalt), red (manganese), yellow (titanium), purple (neodymium), pink, and orange. As faceted gems they are valued (as synthetics) for their clarity, durability, high refractive index and dispersion. The critical angle of YAG is 33 degrees. YAG cuts like natural garnet, with polishing being performed with alumina or diamond (50,000 or 100,000 grit) on common polishing laps. YAG
Mount Garnet, Queensland boasted a water source that never ran dry. Now it is used for a water supply to the township. Fresh water is continually pumped from the Herbert River into Warruma, then pumped out of there into holding tanks for the town supply. At the 2006 census, Mount Garnet had a population of 458. The Mount Garnet area has a number of heritage-listed sites, including: Mount Garnet State School opened on 22 January 1901. A railway was authorised to be built from Lappa, on the then Chillagoe Railway and Mines Company's line, to Mount Garnet by the Mount Garnet Freehold Mining