Zircons are rare minerals with a variety of color. The crystals are Golden yellow, red, brown, yellowish-green and sky-blue tone. The color palette of minerals is created the admixtures of various metals such as iron, copper, zinc, calcium or titanium. Natural zircons are small, pointed crystals with regular faces.
Refined blue or blue minerals are called Starlite. In the jewellery market there are quality Starlite, as a rule, no more than 10 carats. To the higher price category zircons with blue and blue color, without a greenish hue. The rarity of these minerals determines their high cost and popularity among connoisseurs. Colors starlito sky-blue colors is similar with bright blue color Paraiba tourmalines.
Jewelers particularly appreciate the following types of zircons:
There are also copies of rare colour change effect.
Jewelry zircon combines amazing optical effects:
Variance is a game of colored flashes in the gem. Variance of zircon is very high, higher than diamond, this makes it very attractive for jewelry. Natural zircons show a tremendous fire and the change of bright flashes, thanks to this clear, colorless zircons are sometimes used as substitutes for diamonds.
Birefringence - effect of a split of edges in zircons it is very strong and noticeable to the naked eye. The photos birefringence can cause a feeling raspolozhennogo image of the gems. The effect of the split faces helps to accurately determine the zircon from a number of other colored gems.
The effect of "cat's eyes" - a very rare optical effect of the zircon. It is characteristic of the gems in cabochon cut with lengthwise inclusions, through which the light strip is formed on the surface of the gem. She moved with the swaying of the gem.
Clear, colorless zircons are characterized by high refractive index and strong dispersion. These gems after a quality cut is very similar to diamonds. They are amazingly played and glisten in the rays of light falling on their faces. Play of light is more often seen in bright crystals. gems of darker shades play worse.
Gemological uniqueness of zircons consists in a significant range of densities and refraction, beyond the results, explained by the differences in the chemical composition or the presence of voids in the structure of crystals.
The cost of natural gem zircon
Experts believe the zircon is one of the most underrated gems on the market and the forecast increase in cost. Precious zircon has yet to reach maximum market potential, we believe that this aside for a few years. Already we are seeing an increase in demand for this gem not only among collectors, but also famous jewelry houses that produce limited edition products and collection with this beautiful gemstone. The world-famous jewelry with zircons from German companies Hemmerle.
The cost for the zircons of different color varieties are different, but the main price-forming factors are: the mass of the gem, clarity, cut and most important, the degree of color saturation. The most expensive variety is a blue Cambodian zircons. Large rich blue, almost blue samples in the qualitative cutting can cost $280-450 per carat. The lighter color is in the range $150-280 per carat. Yellow, red, brown and colorless zircons are on average $100-200 per carat.
Field jewelry zircons
Jewelry zircon is mined only in a few fields. The best minerals come from Cambodia and Sri Lanka. The gems from these countries have the most diverse color palette that includes instances of a reddish-brown, yellow and green. Interestingly, all Starlite arrive on the market exclusively from Cambodia. Most of the gems becomes colorless color after refining by heat treatment. Along with this produces a small amount of natural colorless zircons in the area called Matara in southern Sri Lanka. Gem of good quality is mined in the deposits in Burma, Thailand, Tanzania, Madagascar and Vietnam.
Note that the zircon blue, Golden-yellow and colourless crystals, which is now at the peak of popularity are sanitized reddish-brown minerals from Cambodia. Interestingly, the results of heat treatment of the crystals are highly resistant.
The elevation of the natural zircons
The quarried raw material of zircon is brown, less orange color. Blue color it acquires after annealing in special furnaces. The color of zircon after heating is changed tocolorless,yellowor orange. 90% of the zircons are heat treated. Heat treatment of zircons is generally accepted Gemological community and does not affect their value, similar to the case withtanzanite. Heating occurs in makeshift ovens-barrels, where is placed the refractory container with the raw material. The container protects the crystal from direct flame, preventing cracking of raw materials. The process takes only a few hours. Sometimes to correct the color of the crystals is heated in two stages. Color change as a result of the annealing is stable.
Common misconceptions about zircons
Rare natural zircon gem because of the similarity in name is often confused with cubic Zirconia (cubic Zirconia), a cheap synthetic gem that is used as imitation diamond. This is not the only name confusion that arises from buyers. Jewelry zircon still confused with similar-sounding Zirconia - metal in the periodic table it is denoted as Zr.