Loose diamonds in retail sales are always supplied with certificate of conformity issued by an accredited center. All jewelry with diamonds manufacturer is also making a document that contains information about the main characteristics of precious stones. These sources can be completely trusted, since the evaluation of quality of diamond is carried out by specialists using the most modern equipment. Just buyer enough to understand that refers to a particular alphanumeric character. Then you can easily learn how to evaluate diamonds on your own.
Characteristics of diamonds are subject to the "rule of the 4CS": carat weight (carat weight); color; clarity (purity); cut (shape and quality of the cut). Usually on the tag jewelry with diamonds you can find the information of this type: 1 Br Cu-57 0,08 2/3A. This means that the decoration contains 1 diamond round shape with 57 facets. Gemstone weight of 0.08 carats. Figure 2 indicates the characteristics of color, and 3 purity. Letter A refers to quality of cut.
So, to begin to learn the characteristics of the diamond, first and foremost, pay attention to its weight in carats. 1 carat (ct) equals 200 milligrams, or 0.2 g. All diamonds are divided into small (up to 0.29 ct), medium (0,30 – 0,99 ct), large (over 1 ct). There is a relationship between the weight of a diamond and its diameter. For example, stone weight is 0.50 ct with perfect adherence to the technical specifications for polished diamonds will have a diameter of 5.2 mm. Respectively, the greater the weight of the diamond, the greater its diameter, as well as the cost.
According to the domestic scale of colors each diamond is assigned a value from 1 (colorless) to 9 (brown). For cut diamonds weighing up to 0,29 ct color range is characterized by a scale from 1 to 7. International system of GIA (Gemological Institute of America) refers to gradation of color letters from D to Z. the Most valuable are colorless or with a slight tint of diamonds, about 1 to 5 colors group (D, E, F,G, H in the GIA system). The cheapest cut diamond with color 5-7 (up to 0.29 ct) or 8-9 groups of color (K-Z on the GIA).
Diamond clarity is another important factor significantly affecting its price. Diamonds, like any other minerals, can have natural defects. Defining their characteristics, number, size and location, the expert assigns to each diamond is the group of purity. In the domestic classification of diamond clarity is indicated by the numbers 1 to 12. And 1 – net under a magnifying glass the diamond; 9-12 – diamondswith inclusions visible to the naked eye. For diamonds up to 0.29 ct of a similar scale has a range from 1 to 9. The system of GIA diamonds with the highest purity group denoted by the letters IF, then there is a gradation of species VVS1, VVS2, VS1, VS2, SI1-SI3, I1-I3. Group purity I3 corresponds to the 11-12 group in the Russian classification.
Finally, review the information on the form and quality of cut. The most popular and expensive is the round cut diamond Kr-57. There are also many fancy shapes: pear (G-56), Marquis (M-55) oval (S-57), Princess (P-65), baguette (B-33), trilliant (T-55) and other fancy shapes are stylish and impressive look in jewelry.
The cut grade in Russian classification is denoted by the letters A, B, C, d where A is best quality, D – unsatisfactory. Under the cut grade refers to the ratio of the linear dimensions and angles, Polish and symmetry. From all these parameters depends on the luster and play of light in the stone. In the GIA system best quality of a diamond is denoted by the word excellent, followed by such gradations as very good, good, worst is denoted as poor.