Emerald is a kind of natural beryl, different green. He, along with sapphire and ruby is included in the "leading three" colored gemstones and has a very high cost. Natural emerald delights pure bluish-green color that is unparalleled among other minerals.
Rich green color of the mineral is determined by the presence of chromium impurities. The admixture of vanadium gives a bluish tint, and the presence of ions of iron gives a yellowish warm tone. There is a division of natural stones colored by chromium impurities and colored impurities of iron and vanadium. If the beryls the green color caused by iron ions, these minerals klassificeret as green beryl. Greenish hues of these minerals are expressed to a lesser extent, and differ from the grass-green shades of emeralds. More saturated colors are green beryls becomes sought after by jewelers when creating their collections.
Emeralds have a high hardness, determined according to the Mohs scale of 7.5 - 8 units. This quality contributes to the durability and great wear of the stones included in the jewelry. A feature of the natural samples is the presence of multiple inclusions and small cracks. This feature reduces the strength, complicating the work of secretsyou and cutters. The main parameters that determine the price are color, clarity and weight. Natural minerals saturated colors are quite rare. Discovery net large stones, in excess of 5-6 carats, is considered a unique event. The price of such instances reaches the value of diamonds of the same size. Traditionally, the purity determined by eye without optical devices.
During the evaluation also focuses on the zonation of the color, as minerals have painted areas of different intensity. Too pronounced zoning reduces value of the stones. Quality cut-out reveals a color palette of emeralds, and can hide a number of natural features such as pleochroism, zoning of color, inclusions. In the jewelry markets, the cost of high-quality emeralds up to 6 - 8 thousand dollars per carat. Top instances is estimated at over 10 thousand dollars per carat.
Often, emeralds are treated, which greatly affects the formation of value. When elevation is used impregnated with cedar oil, resins, polymers, oil, dyes or paraffin. Of course, the price of natural stones is much different from the sanitized copies. The presence of gentrification are able to establish only specialized Gemological laboratories. Note that the refinement method of oiling with cedar oil with similar refractive index, is recognized as the norm of all jewelry companies.
Russian laboratories in the assessment of colour and clarity emerald used the 1988. This document States that the color and quality parameters are determined in accordance with the samples when you create certain conditions. The color is determined according to a 5 - point scale, where 1 corresponds to the saturated color, and 5 – the lightest tone. Instances that are lighter 5 scale marks, referred to as beryl. In determining the colors used are specially certified samples. The definition of purity in accordance with the specifications is also available on a 5 - point scale. Most clean stones with no inclusions are referred to the first group. The group K2 includes the stones that have numerous and well-visible inclusions. The names of the groups K1 and K2, indicate that emeralds of this quality are suitable for faceting under the dome.
International assessment of color is based on the GIA system. It is performed in accordance with special color set GIA GemSet (vsbG-G; tone 3-8; saturation 2-5). Purity is assessed by 3 groups. The best color according to the GIA GemSet is - bG 5/5. Best group of purity - III.
Natural emeralds can have some variety. The first caused by a large number of elongated needle-like inclusions and is called "cat's eye". The second type is called "Trapiche". It is an unusual star-shaped arrangement of six sectors separated by graphite inserts. Emeralds "Trapiche", discovered in Colombia, serve as a valuable prize for collectors worldwide. The stones are such high quality are extremely rare, which greatly increases the value of the found instances.
Modern production is done on a hundred fields located in different countries. The richest deposits are located in Colombia. Accounted for in different years from 55 to 70% of world production. Jewelers include Colombian emeralds to the reference samples for high image quality and color palette that make the stones from Colombia a world-class brand. However, not all of the Colombian findings have high quality. Now, many samples from Brazil and Africa may well be better. Along with Colombia, they also are mined in Brazil (Minas Gerais state), Zimbabwe, Madagascar (malagasi), United States (North Carolina), South Africa, Nigeria, Austria (Habachtal), Russia (the Urals).
Jewelry embellished with emeralds, are some of the most popular all over the world. Ancient members of the nobility took the emerald jewelry the most honorable places. Rich green tones are unusual and in demand now. The cost of jewelry varies quite widely. The price of traditional gold rings with a small stone of average quality categories is in the range of several hundred dollars. Jewelry decorated with high-quality emeralds of large size, there are tens of thousands of dollars.
Most often precious emeralds rimmed with gold, making rings or earrings. Silver very seldom used. Many jewelers used a combination of emerald with small diamonds that flank the green stone. The most popular products with stone, having an average colour saturation. Adornment with this emerald can be worn to work or for social reasons. In the Windows of jewelry stores there are virtually no products with stones over 3 carats. These decorations are mainly made to order. The main condition is the selection of quality emeralds. For women's earrings pretty hard to find a pair of identical copies. Fashion men's rings and rings with emeralds. Jewelry with green gem minerals produce almost all the jewelry house of the world level.