The crystallographic structure of garnets has been expanded from the prototype to include chemicals with the general formula A3B2(CO4)3. Besides silicon, a large number of elements have been put on the C site, including germanium, gallium, aluminum, vanadium and iron.S. Geller Crystal chemistry of the garnets Zeitschrift für Kristallographie, 125(125), pp. 1–47 (1967)
