Among all the precious minerals, natural sapphires are considered one of the most beautiful stones. Although they are significantly inferior in value to diamonds and rubies, except for some particularly valuable representatives of this group. Sapphires of deep blue color from the most ancient times were considered as a traditional jewelry for kings and clerics of the highest rank. Crystals were identified with wisdom and justice, they were attributed healing and magical properties.
Sapphire - what is it
Natural sapphire stone is a common alumina. Its formula is Al 2 O 3 . That is, the mineral is a derivative of one of the softest metals, while the crystal itself is inferior in hardness only to diamond. Its hardness indicators are 9 units. according to moos.
According to the generally accepted jewelry classification, sapphires are not red corundums. Red corundums are rubies. It is also alumina with the same chemical formula, and a red color gives it an admixture of chromium. The affinity of these crystals was discovered back in 1800.
Sapphires include stones of any other color - blue, yellow, black, transparent, etc. In this case, blue crystals are simply called sapphires, and a color characteristic is added to the name of stones of a different shade. That is, they say yellow sapphire, black sapphire, green sapphire, etc.
The color of the stone depends on impurities. So, the blue color gives an admixture of titanium and iron, the yellow tint is due to nickel oxides, the green is from cobalt and magnesium, and the most interesting color is given by vanadium. The presence of the latter element tints the stone in lilac and purple.
Blue sapphires
The most famous are blue sapphires. Pure blue crystals are rare in nature, and it is customary to call blue the entire palette - from light blue to almost black. However, it is considered that true blue sapphires are those stones in which the impurities of a different color are no more than 15%.
If blue is mixed with green, then such a crystal is called fancy, for a bizarre witchcraft shade. The most valuable are saturated cornflower blue sapphires. Faded stones and too dark are cheaper.
Sapphires of other colors
Yellow sapphires are even less common than blue sapphires, and therefore their cost is only slightly lower than that of cornflower sapphires. The color of yellow crystals varies from saturated amber to almost transparent, colorless. Clear crystals are often confused with diamonds. According to Eastern religions, yellow corundums can be worn on the body only if the stones are free from defects.
Black corundums are quite common, but their value is noticeably lower. Jewelry with dark crystals is too strict, and not so pleasing to the eye.
The birthplace of pink corundum is Madagascar and Sri Lanka. These crystals have a delicate shade of pink, and are in great demand. They are very similar to pink diamonds, but are cheaper.
Green corundums are often not green in the full sense of the word: the color of the stone is obtained by the imposition of yellow and blue impurities.
The crystals, which are called the color of the lotus or padparaj, have an unusual yellow-orange tint with red reflections. Jewelers distinguish them into a separate, rather large group of corundums.
Star sapphires
Sometimes, needle-like inclusions of titanium oxide (rutile) are formed in alumina crystals. Thus, a star with six rays is formed in the crystal lattice. Or less often - with twelve. This happens when two needle-shaped rutile formations are superimposed on each other at once. Such natural sapphires are called star-shaped.
Corundums with asterism can also be of different colors, but blue and dark crystals are more common.
Application
Natural sapphire is a gemstone that is mainly used in jewelry. But there are artificial stones, which are also massively used to create jewelry. Chemically pure alumina, without impurities, is absolutely transparent - such stones are called leucosapphires and are used in ophthalmology, for the production of precision optical parts, protective glasses in aviation, for the manufacture of laser technology, as well as elements of various installations where high temperature resistance is required.
What can I buy instead of sapphire
Since tons of artificial sapphires are produced annually in the world, people are wondering how to distinguish natural sapphire from counterfeit? For a real natural crystal, the following simulations can produce:
- glass or similar material;
- externally similar natural stones, for example, tanzanite;
- synthetic sapphire.
All three options are very different from each other. Glass or hard plastic means that the buyer is offered cheap jewelry. And this is definitely a fake. Tanzanite is a natural mineral, but it is much less valuable than real corundum. So this is also a hoax. While synthetic sapphire is an absolute analogue of natural sapphire in all respects. And you can call it a fake only in one case - if it was sold as natural, with a description of the origin. Even the word “natural” on the tag does not give the right to consider the crystal to be natural, not grown. After all, synthetic sapphires are also 100% natural, they are also alumina with impurities for color. Only nature has grown corundums for thousands of years, and laboratory assistants for 2-3 weeks.
How to distinguish synthetic stones from natural ones
- If the stone is clean, and its price is moderate, then most likely it is synthetic.
- Glass has rounded edges. The natural crystal is too hard for such a cut and has sharp edges.
- Glass is easily scratched, while in the present it is very difficult to leave a mark.
- The presence of defects, inclusions, inclusions indicates the natural origin of the crystal.
- Air bubbles in a perfect stone indicate that it was grown in a laboratory.
- Sapphire is slightly heated in the hand, and tends to change color under ultraviolet radiation.
In fact, an ordinary person can only calculate explicit jewelry. And in most cases, you will have to contact a jeweler for an assessment of natural sapphire. In the workshop, stones are studied using a refractometer - a device that measures the angle of refraction of rays. Based on this indicator, as well as in appearance, color, purity, the jeweler will give his opinion.
We must not forget that natural sapphires undergo alterations. For example, a jeweler is brought a chain of silver with natural sapphire. And after studying, he finds out that the stone is natural, but with defects. And the cracks on it are smeared with synthetic filler. Similarly, on stellate sapphires with weak asterism artificially reinforce this effect. In any case, only a specialist can determine the true value of a crystal.
Price
How much can a real sapphire cost? The price varies greatly from many factors - the origin of the crystal, its weight, purity, cut, etc. For example, in a jewelry salon, earrings with natural sapphire of 2 carats cost from 30 thousand rubles. There are many offers on the Web to buy natural sapphire and the price range is impressive: from 500 rubles. for a large stone up to 5000 per 1 carat. A ring with natural sapphire 0.33 carats in the famous jewelry chain can be purchased for 12-20 thousand rubles.
If you look at prices on the world market of precious minerals, then most often corundums are found and sold at a cost of 100-300 dollars per carat. Valuable items from Burma and Kashmir will cost several times higher.