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
Gemstone Warrior Gemstone Warrior Gemstone Warrior is an action role-playing game written by Canadian developer Paradigm Creators for the Apple II and published by Strategic Simulations in 1984. It is an action-adventure title set against a 2D screen with the player controlling an armored figure that they would move from area to area in search of treasure and the pieces of the stolen Gemstone. "Gemstone Wariror" was SSI's first game to sell over 50,000 copies in North America. The game was ported to the Commodore 64, Atari 8-bit family, and Macintosh. In addition, the games were ported to the N7 Japanese system.