So many people have asked me why all birthstones are genuine stones, some very expensive, yet December is a cheapo colored Zirconia! Everyone knows that Cubic Zirconia is a very inexpensive synthetic stone that usually is used instead of diamonds. They come in a wide variety of colors and generally cost $30 or less.
But Blue Zircon is not Zirconia. Zircon is a natural stone that occurs in an array of colors. Its varied palette of yellow, green, red, reddish brown, and blue hues.
Blue the most popular colored Zirconium, is produced by heat treatment of brown zircon. But not all brown zircon will turn blue when heated; only some zircon has the right physical structure for this to occur. This is why most blue zircon comes from certain sources in Cambodia or Burma.
Blue zircon has some unique properties that make it very popular with gemstone fans. Not only does zircon have outstanding brilliance, but it also has very strong dispersion, the tendency to split white light into the spectral colors. Zircon also has very obvious double refraction, with a wide variance between the two refractive indices. This can be often be observed with the naked eye when you look down through the table of a cut zircon; you will observe facet doubling that makes the facet edges appear blurred.
So now you know. Blue Zircon is a member of the Zirconium family and not the Zirconia family. It is a natural stone and therefore somewhat costly. It is also quite beautiful to feature in jewlwery such as rings, pendants and earrings. It is especially sharp in white gld. Folks born in December are very lucky indeed!