Zircon

Zircon is the oldest known mineral on earth, with the first zircons found about 4.46 million years old, probably coming from Western Australia. The name zircon is thought to come from the Persian word zargun which means gold-colored, but zircon comes in a wide range of colors. Over the years, zircon has lost much of its popularity from being compared to cubic zirconia a simulated gem, when really, these two gems are very distinct. Blue Zircon is the birthstone for the month of December.
Zircon, like many minerals are colorless in their pure form and get the variety of brilliant hues from impurities. Zircon in its colorless form was the original diamond substitute used. Like diamonds, they have brilliant luster, but unlike diamonds they tend to wear along facet edges over time. Blue zircons demand the highest prices, with red following close behind. Three different terms are often used to describe the color of zircons; hyacinth (yellow, yellow-red to red-brown zircon), jargon (straw-yellow to almost colorless), and starlight (greenish blue zircon, created by heating).

Origins

Zircon is found in Australia, Brazil, Cambodia, Korea, Madagascar, Mozambique, Myanmar (Burma), Nigeria, Sri Lanka (Ceylon), Tanzania, Thailand and Vietnam.

Properties, Treatments & Lab Created

Zircon is rated a 7.5 on the Mohs scale.

Brown zircons are commonly heat treated to create colorless and blue zircons. This treatment is not always permanent and ultraviolet rays (sunlight) can sometimes change the stones appearance.

There is no lab created zirconia, but it is common that cubic zirconia is thought of as a simulant of the natural zircon, which is not the case. Cubic zirconia is a man made material that has completely different properties than natural zircon.