Gem - mineral, rock, organic or synthetic material that can be collected and used for jewelry. This is a natural process and worked precious, jewelry and puonieji stones, organic gems. Minerals are often found in nature called pusbrangakmeniais. Currently, among the experts is the presumption that all the stones are known as precious stones, the line between precious and semi-precious stones disappeared. However, the simplification of these concepts, however, the stones with unusual properties have been attributed to all the usual stones. Some authors classify the rocks in the true sense of gems ( diamonds , sapphires , rubies , emeralds , spinel, topaz , alexandrites, aquamarine , heliodor, morganitai) gems in the broad sense (quartz, etc.)., puoniuosius rocks (feldspar, jade , etc..) , rare collectibles stones ( Azur , apatite , diopsidas, etc.) and synthetic gems.
According CIBYO (stone Jewellery, silver dribini, diamonds and pearls International Confederation) classification of jewelry stones are divided:
Natural materials:
- precious stones, jewelery and puonieji
- organic material. Ammonite, ivory, jet, amber, coral, pearl, pearl, petrified wood, tortoise shell
Man-made products:
- synthetic stones. Create a person, but the physical and chemical properties of the real
- multiple stones. It consists of artificially linked parts - can be both real and synthetic stones
- imitation stones. Partially or fully developed human, has the effect of stone, but stones do not have certain inherent chemical and physical properties and crystal structure
- reconstructed stone. Produced by fusing or compacting of natural materials into a single article
- simulation of organic matter. No specific chemical and physical properties, but also mimics the outside, the color effect
There is a popular gemstone categorization is based on the price and the approximate boundaries are: traditional gemstones, new classics scholars gems, collector gemstones, and precious stones available. All these categories are approximate price range, but certainly rarer color or transparent stones may cost more.
Traditional gemstones - a ruby , emerald and blue sapphire . Because of its history and unfading charm, these gems are generally valued more than other colored gemstones. Most of the same quality rubies and emeralds are more expensive than sapphires because of their rarity. For a good quality diamond you can pay 250 dollars to 10,000 dollars for karate, although it is not the limit.
New Classics - a rising star jewelry. This is the Tanzanite, tourmaline , aquamarine , imperial topaz , and garnet tsavoritas , especially in larger sizes. Karats of gems from 50 to 100 dollars a carat tsavorito good quality can cost $ 3,000.
Connoisseurs of precious stones are for the more specialized market because they are much less frequent. This is a black opal , jade , pink topaz , chrysoberyl cat's eye, sapphires of various colors, as well as pomegranates , deimantoidai , alexandrites with practically no longer a raw form. These stones cost $ 250 dollars to 5000 dollars for karate, but good quality alexandrite carat can cost 10 thousand dollars for karate.
Collectors are so precious that it is difficult to obtain, and it is a spinel, Zirkons , moon rocks , and so morganitas. Most of this cost category, bright red and pink spinel - even a few thousand dollars for karate, but other costs in this category brangakemeniai not thousands, but hundreds of karate.
Available gemstones are in color, the quality is relatively very low cost. This is the amethyst , white opal , lemon , ametrinai , Peridot, pirpotai pomegranates , blue topaz , jolita , chromium diopsidai, kunzitai, andalusite, and other stones such as lapis lazuli , turquoise , onyx , chrysoprase , Jade and amber . These high-quality carat stone costs from $ 5 to $ 100.
Beautiful appearance of your precious gains after treatment (grinding and polishing). Some precious jewelery inappropriate because it is too soft or brittle, but because of its beautiful appearance, they may be exhibited in museums and held in various locations as decorative element. Stone gloss durability depends on its hardness.
Precious value is determined by various factors, the following are commonly used criterion of value.
Transparency
Transparency means that the stone should be free of spots, dots and so on., Especially those who are sanded facetiniu way. Often the term - "invisible eye defects. Also, different types of gemstones and who is allowed to have inclusions, such as emerald, with visible opacity is seen much better than the same amount of grenades.
Color
The color is a factor which is equally applicable to all the jewels. I envy the color of diamonds are standard, while the colorless diamond as silver topaz should be as transparent as possible. Preferably, the color of colored gemstones as much as possible, more intense. Light amethyst and aquamarine are valued much less intense than the color. The same kind of stones are still grouped by color, such as pomegranates piropai is ruby red, blood red, purple, red raspberries. Although the purple-red raspberries pomegranates are valuable, but your personal opinion, what color you like is just as important. The most valuable sapphires are a clear blue color without any greenish tint. Meanwhile, the most prized opal is daugiaspalviai.
Processing
Gems can be processed in different ways. Sanding can be diamond (round), emerald (Triangle), oval, pear, marquis shape. Grinding quality is determined must polished corners of uniformity, shape retention, and should not be any cracks.
Precious rarity
The greater the supply, and if it exceeds the demand, the lower the price and precious stones. It is therefore extremely expensive stones such as diamonds, and opal, the supply is controlled, and it never exceeds the demand. However, there is no way that the stones are extremely rare and expensive, and vice versa. Pavyzdiui, beryllium belongs to the group biksbitas gem is very rare, we can say a million times less dense than the same stone beryl group, the emerald, but only a few tens of ezempliori price times the price of emerald. Also, much depends on the ad. The 1980s. Tiffany's jewelers began to use an unknown to anyone very interesting green grenade called tsavoritu, and since then it has become quite popular as well as its price rose. A similar story happened with Tanzanite gem.
Beauty
This is a subjective criterion, but it seems that it includes the previously mentioned transparency, color processing.
Naturalness
There are currently developed manufacturing industry sitnetini gems, but buying gems to be sure whether this is genuine or fake stone. Of course, natural stones are much more expensive than synthetic. It is also sometimes improve the color, surface imperfections are used in various instruments, such as various oils, resins, glass, plastic, wax, as well as reconstruction, stabilization and staining, in addition to the use of laser spots and change. According to Lithuanian law, vendors must be certified only to diamonds, sapphires, emeralds, rubies, and alexandrite, other precious stones, their veracity patvirtiniantys documents are not required. Therefore, most vendors still rely on, or in case of doubt patiktrinti gems, this service is provided by the Lithuanian Assay Office branch in Vilnius.
