Zircon

Gemstone : Zircon Birthstone Month : Zircon is associated with the birthstone months of December and October. Zodiac : Zircon is not associated with any particular zodiac sign. Chemical Symbol : ZrSiO4 Chemical Make-up : Zircon is a Zirconium Silicon Oxide. History & Lore : The name Zircon is believed to of been derived from the Persian word 'zargun' which means “gold-colored”. Zircon is however a beautiful natural gemstone that can be found in various colors. An interesting fact about Zircon is that geologists can determine how long a certain stone has existed by using modern analytical techniques. This is possible because Zircon crystals accumulate atoms of Uranium which decay to lead at a known rate. By measuring the relative abundance of the two types of Uranium and Lead in Zircon's chemical composition, scientists can then determine how old it is. Zircon is so far the oldest mineral known to man, with the oldest specimens to date being found in Western Australia (4.404 billion years old), and Chile (4.6 billion years old). Colorless Zircon specimens have long been a popular substitute for diamonds. This is because of Zircon's high refractive index, luster, and light dispersion. Today Zircon is often overlooked, probably due to its name being similar to the synthetic, man-made Cubic Zirconia, also a diamond substitute. In the middle ages, Zircon was believed to aid sleep, promote honor, and to bring prosperity and wisdom to its wearer.

Availability : Zircon is readily available at affordable prices. Natural blue colored Zircon is somewhat rare and because of this blue colored Zircon gemstones demand a premium. Sources : Zircon deposits occur worldwide. Noteworthy deposits include: Australia, Brazil, Cambodia, Canada, India, Italy, Myanmar (Burma), Nigeria, Norway, Russia (Ural Mountains), Sri Lanka (Ceylon), Thailand, United States, and Vietnam. Evaluation : Zircon is rated at 7 to 7.5 on Moh's Scale of Hardness and though a hard and durable gemstone, Zircon should be worn and stored with care as it can abrade and facets can chip. For many years, colorless Zircon was the most popular variety. This was due to it's striking resemblance to the Diamond. Today however blue Zircon is the most popular color. Blue Zircon is found in pastel blue and occasionally bright blue. Zircon is also available in green, dark red, yellow, golden-yellow, brown, and orange colors. Zircon has a very high refractive index meaning it has the ability to strongly bend light, in fact, it is strikingly similar to that of the diamond, explaining why it has been a popular substitute. Zircon also has a beautiful luster and a high light dispersion that accounts for the stone's beautiful “fire”. Zircon is found in both a low and a high variety. The two varieties are separated by their difference in refractive index and specific gravity. The “high type” naturally has a higher refractive index and specific gravity than the “low type”. The differencea are a result of the decay of Uranium and Thorium, elements that are naturally present in Zircon. The radioactive decay from the Uranium and Thorium causes the crystal structure of the low type to break down over millions of years. Fortunately, heat-treatment can reverse much of this deterioration and to convert low type into high type stones. Common Cuts : Zircon is most commonly and almost exclusively faceted into cuts that will allow the best brilliance and fire to be exhibited. Routine Enhancements : Zircon displaying a color that is not considered to be of gem quality is often heat-treated to produce a more desirable color. In general, brown crystals are most often used to produce (depending on the amount of heat applied), colorless, red, golden-yellow, and blue Zircons. Care & Cleaning : Zircon is a relatively hard gemstone, though it should be stored carefully because it can abrade and facets can chip. Zircon is best cleaned using warm soapy water and a soft brush to remove any collected dust or grease. As with most gemstones, Zircon should be kept away from household chemicals and exposure to excessive heat as both can cause permanent damage to the stone. Zircon jewelry should always be stored in a fabric-lined box away from other jewelry items to avoid chipping and scratching.