Zircon (Zirconium Silicate ZrSiO4). Mohs hardness: 6.5 – 7.5 Refractive Index: 1.777 – 1.987
Lustrous, fiery, and considered to be among the oldest minerals on earth, the Zircon is one of the most fascinating gemstones in existence. Known for its durability, as well as its resistance to chemical attack, scientists have called the Zircon, a “tiny time capsule”, describing it as “the most reliable natural chronometer that we have when we want to look at the earliest part of Earth history.”
The intriguing history of a Zircon begins with its formation: formed by crystallization from a magma or in metamorphic rocks, the Zircon possesses a remarkable ability to not only survive geologic events – some of which may last millions of years – but to record those events in its crystal rings, similar to the rings found in tree trunks. Imagine wearing one of these!
These ever-intriguing gemstones sometimes offer another unusual feature: radioactivity. In a rare example of an animated life cycle in a stone, these radioactive elements can cause metamiction, an ongoing process in which the stone’s inner crystal structure is slowly destroyed.
While this very slight radioactivity is at levels that pose no health risk when used in jewelry, the trace elements trigger the vibrant color diversity found among Zircons. Ranging from yellows and browns, oranges and reds, greens and blues, it is believed that the Zircon’s name comes from the Persian word for the stone, zargun, which means “gold-colored”.
The Zircon also appears in ancient Hindu poetry, as the leaves of the Kalpa Tree, a glowing tree covered in gemstone fruit. The Zircon has been considered as a talisman for travelers, a deliverer of financial success, and a protector against occurrences such as jealousy, envy or lightning strikes, as well as harmful energy emitted by celestial bodies in our solar system. Each color offers a different benefit: for instance, a pink Zircon allegedly aids the wearer in astral travel; light yellow boosts sexual power; and red promotes healing. The colorless Zircon, which is unfortunately often confused with the artificial cubic zirconia, is thought to stimulate mental awareness and clear thinking.
The Zircon’s high refractive index and strong dispersion – its fire – gives the stone its great brilliance. Legend has it that the Zircon’s owner must maintain the gemstone’s shine – otherwise its power transforms from positive to negative.
An important identification mark for all Zircons, with the exception of the green variety, is the strong double refraction easily seen under the loupe at the facet edges. The illusion of “double refraction” is actually the doubling of the facet junctions, thereby creating a line where two facets meeting in the back appear either doubled or blurred when viewed from the top. Being responsive to a basic heat treatment, the Zircon will glow in bright yellow or soothe in pensive blue, both considered to be the most desirable colors of the Zircon.
Zircon is mined in Cambodia, Sri Lanka, Thailand, Myanmar, Australia, and other countries.
Facts about the Zircon (courtesy of the Gemological Institute of America Inc. To learn more about GIA, click here: http://www.gia.edu/ )
Zircon is a gemstone that’s not commonly known among jewelry buyers, which is a shame considering the number of beautiful colors it comes in. These include earth tones such as cinnamon, sherry, yellow, orange, and red. Among those who are familiar with this gem, zircon is especially admired for its attractive blue colors. Although collectors clearly love zircon’s color variety, consumers seem most enamored of just one hue: blue. Gem dealer reports indicate that at least 80 percent of zircons sold are blue.
Color: Some zircons display warm autumnal earth tones such as yellowish and reddish brown, inspiring fashion trends. Red and green zircons have market value as collectors’ stones, and cat’s-eye zircons occasionally appear on the market. There are also colorless zircons.
Because they’re in greater demand, blue zircons usually command higher prices than any of the other varieties. Even though gem buyers can satisfy their demand for blue gems with top-grade topaz at significantly lower cost, blue zircon continues to sell well. Industry analysts believe that blue zircon has yet to reach its full market potential.
Clarity: Zircons are relatively free of inclusions, but many untreated zircons have a cloudy or smoky appearance. If it’s extreme, it can be a negative factor with buyers. In Victorian times, this smokiness made zircon a popular gem for mourning jewelry.
Cut: It’s a challenge to cut zircon because the gem is brittle. Cutters usually fashion zircon in the brilliant style to take advantage of its luster and fire. A modification of the brilliant cut, known as the “zircon cut,” uses eight extra facets around the gem’s lower portion, called the pavilion. This isn’t seen very often today because of the extra labor costs involved. Zircon can also be found in step cuts, which have rows of parallel facets, and mixed cuts, which are a combination of brilliant and step-cut facets.
Carat Weight: The supply of zircon is generally limited, and typical sizes depend on color. Blue or green stones normally range from 1 carat to 10 carats and yellows and oranges up to around 5 carats. Reds and purples are usually smaller.
Interested? Click this link to see our amazong selection of the finest Zircons here at Gemcal.com