Among all 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 especially valuable representatives of this group. Deep blue sapphires have been considered a traditional decoration for kings and clerics of the highest rank since ancient times. Crystals were identified with wisdom and justice, they were credited with healing and magical properties.
Sapphire - what is it
Natural sapphire stone is a common aluminum oxide. Its formula is Al2O3. 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 Mohs.
According to the generally accepted jewelry classification, sapphires are non-red corundums. Red corundums are rubies. This is also aluminum oxide, with the same chemical formula, and the red color is given to it by an admixture of chromium. The affinity of these crystals was discovered back in 1800
Sapphires include stones of anyof a different color - blue, yellow, black, transparent, etc. At the same time, 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 the impurities. So, the blue color gives an admixture of titanium and iron, a yellow tint is obtained due to nickel oxides, green - from cob alt and magnesium, and vanadium gives the most interesting color. The presence of the last element tints the stone in lilac and violet.
Blue sapphires
The most famous are blue sapphires. Pure blue crystals are quite rare in nature, and it is common to call blue the entire palette - from light blue to almost black. However, true blue sapphires are considered to be those stones in which impurities of another color are not more than 15%.
If blue is mixed with green, then such a crystal is called fantasy, for a bizarre magical shade. The most valuable are rich cornflower blue sapphires. More faded stones and too dark are cheaper.
Sapphires of other colors
Yellow sapphires are even rarer than blue sapphires and are therefore only slightly less expensive than cornflower blue sapphires. The color of yellow crystals varies from deep amber to almost transparent, colorless. Clear crystals are often confused with diamonds. Yellow corundum, according to Eastern religions, can be worn on the body only if the stones do not havedefects.
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 high 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 superimposing yellow and blue impurities.
Crystals, which are called the color of the lotus or padparadscha, have an unusual yellow-orange hue with red reflections. Jewelers distinguish them into a separate, fairly large group of corundums.
Star sapphires
Sometimes needle inclusions of titanium oxide (rutile) are formed in aluminum oxide crystals. Thus, a star with six rays is formed in the crystal lattice. Or less often - with twelve. This happens when two needle-like formations of rutile are superimposed on each other at once. Such natural sapphires are usually 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 also artificial stones, which are also massively used to create jewelry. Chemically pure aluminum oxide, without impurities, absolutely transparent - such stonesThey are called leucosapphires and are used in ophthalmology, for the production of precise optical parts, protective glasses in aviation, for the manufacture of laser technology, as well as elements of various installations where resistance to high temperatures 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 a fake? For a real natural crystal, the following imitations can be given out:
- glass or similar material;
- outwardly 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 it's definitely a fake. Tanzanite is a natural mineral, but much less valuable than real corundum. So this is also a scam. Whereas 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 natural, not grown. After all, synthetic sapphires are also 100% natural, they are also aluminum oxide with impurities for color. Only nature grows corundum 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 pricemoderate, it is most likely synthetic.
- Glass has rounded edges. Natural crystal is too hard for this cut and has sharp edges.
- Glass scratches easily, while real glass is very difficult to leave marks.
- 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 heats up slightly in the hand, and tends to change color under ultraviolet radiation.
In fact, an ordinary person can only figure out explicit jewelry. And in most cases, you will have to turn to a jeweler to evaluate 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 issue his opinion.
We must not forget that natural sapphires are also reworked. For example, a jeweler is given 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 star sapphires with weakly pronounced asterism, this effect is artificially enhanced. 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 depending on many factors - the origin of the crystal, its weight,purity, cut, etc. For example, in a jewelry store, earrings with natural sapphire of 2 carats cost from 30 thousand rubles. There are many offers to buy natural sapphire on the Web 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 a well-known jewelry chain can be purchased for 12-20 thousand rubles.
If you look at prices on the world market of precious minerals, then corundum is most often found and sold at a cost of 100-300 dollars per carat. Valuable items from Burma and Kashmir will cost several times higher.
