What are the colors of sapphires?

Since ancient times people have loved to adorn themselves. At first it was simple wreaths and necklaces of bright colors, then shells and beautiful minerals. Later, people learned to process natural, often nondescript crystals so that they became true treasures. This article focuses on sapphires.

Sapphire is one of the most beautiful and expensive natural gemstones, and it has been almost always since ancient times, when man learned to mine and process these natural crystals.

Sapphire, like its fellow ruby, belongs to corundum - a mineral, the basis of which is alumina with various impurities that color crystals in different colors. There are classic and fantasy sapphires. The first group is blue crystals of various shades. Well, all the other corundums, except the rich red ones, are classified as rubies.

The main parameters that estimate the color of gemstones, including sapphires, are hue, color saturation and lightness. The shade standard for fantasy sapphires is not due to the variety of their colors. And for classic blue crystals, the best is considered to be a cornflower blue - the color of sapphires mined in Kashmir.

Sapphires are considered strong talismans. Many sources write that they help from the evil eye, damage and deception, contribute to the attainment of wisdom and tranquility. Seafarers and travelers liked to wear it, especially they liked stones-asterias (star-shaped sapphires).

The color of the stone depends on its composition. Even a small presence of impurities can drastically change the colors and purity of sapphire.

The color saturation is largely dependent on the number and percentage of foreign inclusions. In a simplified scheme, blue sapphires are divided into bright, medium and light stones. Professionals use when evaluating crystals of 5 degrees of lightness and 3 categories of saturation.

Colored sapphires come in a wide variety of colors, excluding, as mentioned above, a rich red color.

The most expensive are the rich blue gems, followed by the stones of pink-orange color (“padparaja”, which means “lotus flower”), then pure pink crystals.Yellow transparent sapphires and blue opaque asteries (stones, on the polished surface of which a 6- or 12-ray star is clearly visible) occupy the 4th place by the most expensive. The steps below are orange, green, purple gems, as well as sapphires, which have an alexandrite effect - that is, they change color depending on the light. Colorless stones, as well as black simple and stellate ones, are the least appreciated. In fact, it is not entirely correct to call black sapphires black - they are blue, simply because of the high color saturation, they appear dark and opaque.

Sometimes there are crystals, one part of which is painted in one color, for example, blue, and the second - in the other, for example, yellow. Such stones are called polychrome, or multi-colored, they are quite highly valued due to the rarity.

When choosing jewelry with any precious or semi-precious stones, require a certificate confirming the natural origin of the mineral. Nowadays, many gems are grown artificially in autoclaves. To the naked eye they can not be distinguished from natural. But there is a significant difference in price, because natural sapphires are very, very expensive, and this already creates opportunities for all sorts of scams. Therefore, do not forget about the certificates, and in the case of the acquisition of large stones, do not be lazy to order an examination, because it is very easy to be deceived.

There is an easy way to check the naturalness of the stone: send a light from an ultraviolet lamp at it Natural crystals should turn green while synthetic ones should not.

When viewing the certificate, pay attention to the evaluation of the stone, for example, 1/2. The first figure indicates the color of the stone (1 - blue), and the second - the category of quality (depending on the purity of the stone and the level of transparency of the crystal). Quality categories total 4. The first one includes stones of the highest purity and transparency, in which there are practically no defects. The second one includes transparent sapphires with worse quality - with minor defects or with too saturated color. In opaque stones of the third category, defects can be seen with the naked eye. Well, the fourth group includes muddy crystals with pronounced flaws.

Also, do not forget to see whether the stone belongs to the sanitized or not. To improve the quality, most natural sapphires are thermally treated, that is, heated. This allows you to change the color of the stone, increase its transparency, etc. This treatment does not affect the physical properties of the mineral, but non-refined natural sapphires are valued much higher than those treated.

Look through the stone at the light, the best natural. Inside the crystal, one can often notice microcracks, which reduce the quality, and, accordingly, the price of the stone. Rate the cut of the stone. Sometimes, due to improper processing or unfair polishing, the appearance of the gem seems to fade, not reflecting all its possible beauty.

The price of crystals also strongly depends on the country of their production. The most expensive stones are those mined in Kashmir, Sri Lanka and Tanzania. The second are Burmese and Thai crystals. Following - mined in all other countries of the world, except Australia, as Australian sapphires are on the bottom line of the price rating of these minerals. It should be noted that the Kashmir field has already been developed and closed. There are also several corundum deposits in the Russian Federation - on the Kola Peninsula (blue, greenish, cornflower blue) and in the Urals (gray-blue).

The properties of sapphire are described below.