GIA Gem Project
Zircon

Photo by Robert Weldon/GIA, courtesy Dr E. J. Gübelin Collection
GIA Collection 33723
Although colourless when chemically pure, zircon is typically yellow-brown to brown. It also comes in red, blue, purple, and green. Because of its high brilliance and dispersion, colourless zircon has sometimes been used as a substitute for diamond in jewellery.