Instruction
1
Color
The color of the sapphire is determined by experts gemologists visually, when compared with reference specimens. It is characterized by a combination of hue, saturation and lightness. The main color tone of the stone is a pure spectral blue, valid secondary colors – purple and green. Sapphires are also divided into five categories on the lightness and three categories of color saturation. However, for commercial purposes is usually applied a simplified classification of sapphire in color, which includes only three groups. First - bright blue sapphires; the second - medium-blue sapphires; and the third light blue sapphires.
The color of the sapphire is determined by experts gemologists visually, when compared with reference specimens. It is characterized by a combination of hue, saturation and lightness. The main color tone of the stone is a pure spectral blue, valid secondary colors – purple and green. Sapphires are also divided into five categories on the lightness and three categories of color saturation. However, for commercial purposes is usually applied a simplified classification of sapphire in color, which includes only three groups. First - bright blue sapphires; the second - medium-blue sapphires; and the third light blue sapphires.
2
Purity
The purity of the sapphire is also defined visually by the naked eye and with a magnifying glass with 10x magnification. Taken four groups according to the purity. The first is almost perfectly transparent sapphires without defects or with isolated small defects that are visible only under considerable magnification. The second - transparent stones with a few minor blemishes and natural inclusions that are not visible to the naked eye. Third - sapphires with a partial loss of transparency, with defects and inclusions that are very visible even to the naked eye. Fourth - sapphires with a marked or complete loss of transparency, with numerous, clearly distinguishable defects and inclusions (or defects are rare, but very large).
The purity of the sapphire is also defined visually by the naked eye and with a magnifying glass with 10x magnification. Taken four groups according to the purity. The first is almost perfectly transparent sapphires without defects or with isolated small defects that are visible only under considerable magnification. The second - transparent stones with a few minor blemishes and natural inclusions that are not visible to the naked eye. Third - sapphires with a partial loss of transparency, with defects and inclusions that are very visible even to the naked eye. Fourth - sapphires with a marked or complete loss of transparency, with numerous, clearly distinguishable defects and inclusions (or defects are rare, but very large).
3
Weight
Weight of sapphires are measured in carats (1 carat equals 200 mg). Small stones of 1-2 carats are fairly common. Larger are considered sapphires 5 carats. They are very rare. The cost of 1 carat weight of the stone, depending on its color and purity, can reach $ 4,000.
Weight of sapphires are measured in carats (1 carat equals 200 mg). Small stones of 1-2 carats are fairly common. Larger are considered sapphires 5 carats. They are very rare. The cost of 1 carat weight of the stone, depending on its color and purity, can reach $ 4,000.
4
Cut
Main ways cut sapphires – faceted and cabochon. From the facet most common cut is round, but often applied also fancy: "heart", "emerald", "Marquis", "oval" and "pear". Cabochon – a way cut in which the stone is given a round or oval convex polished surface. In this way treated sapphires with a significant loss of transparency and a large number of defects. Cut opaque sapphire cabochon with needle-like inclusions of the mineral rutile (so-called "star" sapphires) allows to identify the effect of asterism – the appearance of moving over the surface of a star with 6 or 12 rays.
Main ways cut sapphires – faceted and cabochon. From the facet most common cut is round, but often applied also fancy: "heart", "emerald", "Marquis", "oval" and "pear". Cabochon – a way cut in which the stone is given a round or oval convex polished surface. In this way treated sapphires with a significant loss of transparency and a large number of defects. Cut opaque sapphire cabochon with needle-like inclusions of the mineral rutile (so-called "star" sapphires) allows to identify the effect of asterism – the appearance of moving over the surface of a star with 6 or 12 rays.
Note
The quality and price of the stone is very much influenced by its origin. Considered the most high-quality Kashmir sapphires. They have a cornflower blue color and a silky luster. Since the field in Kashmir is no longer being developed, these stones represent jewelry rare and fabulously expensive. Also valued Ceylon sapphires, which are characterized by less intense light blue color. Siamese sapphires from Thailand are much inferior to them in price. Up to 80% of all sapphires mined in Australia, but these stones are the cheapest because they are very dark, with a greenish tinge, low purity.
Abroad adopted a different system of assessing the quality of faceted sapphires, proposed by the American Gemological Institute (GIA). The correspondence between the Russian and Western systems: a first group of clean – VVS (very very small inclusions), the second VS (very small, small inclusions) – SI (small, but noticeable inclusions), the fourth I (inclusions visible to the naked eye). Keep in mind that natural sapphires, unlike diamonds, are not completely devoid of defects, so the category of IF (clean under a magnifying glass) is unacceptable for them. If the seller offers you the sapphire category IF, or fake, or cultured stone.
Abroad adopted a different system of assessing the quality of faceted sapphires, proposed by the American Gemological Institute (GIA). The correspondence between the Russian and Western systems: a first group of clean – VVS (very very small inclusions), the second VS (very small, small inclusions) – SI (small, but noticeable inclusions), the fourth I (inclusions visible to the naked eye). Keep in mind that natural sapphires, unlike diamonds, are not completely devoid of defects, so the category of IF (clean under a magnifying glass) is unacceptable for them. If the seller offers you the sapphire category IF, or fake, or cultured stone.
Useful advice
In most cases, the tag jewelry with sapphire, you specify only weight, group, color and clarity, for example: "0,55 ct 2/2". The quality of the stone on this information as follows: weight of 0.55 carats (110 mg), stone medium blue, clear, defects are few and visible only at high magnification.