The value of diamonds is the four internationally recognized standards 4C (namely, the English abbreviation of weight, color, transparency and cut).
1. carat: the weight of diamonds is calculated in carats, and 1 carat is equal to 0.2g or 100 minutes. The conventional division is: small diamond 0.0 1 carat -0.24 carat (commonly known as 24 cents); 0.25 -0.99 carat medium diamond; Large diamonds exceeding 1 carat.
2. Color: After the rough diamonds of various colors are processed and polished, there are five common diamond colors: colorless, yellowish, yellowish, yellowish and yellowish. As for pink diamond, blue diamonds, green diamonds and black diamonds, they are rare in the world and are mostly regarded as treasures. Colorless diamonds used for setting are the most common, followed by yellow. China's diamond color grading system is applicable to the mainland and Hong Kong, with colorless as the highest grade, numbered100; Close to colorless, yellowish and light yellow 98-75; The following 75 are no longer members of the gem family. Color d is 100, e is 99, f is 98, g is 97, h is 96, I is 95 and j is 94. DE is extremely white, FG is excellent white, H is white, IJK.
Comparison table of fineness grades of various diamonds
Characteristics of GIA and CIBJ's macro observation in China.
D extremely white (the finest white) 100 is generally colorless by naked eye observation.
Very white (best white) 99
F fine white) 98
G jingbai) 97
H white) 96
I diamonds are slightly white) 95 is less than 0.2 and no color can be felt. Big diamonds can feel the presence of color.
J 94
K colored white) 93
L 92
M coloring 9 1 generally perceived by the naked eye as colored.
Hong Kong's evaluation of diamond color is that colorless to yellow is divided into 100 colors by colorimeter, so it is called "Baise Grade", which is adopted in China. Gemological Institute of the United States is colorless to yellow, and it is divided into D, E, F, …, U, V, W and other color grades, which are adopted by De Beers Company of South Africa.
3. Clarity: Transparency refers to the degree of impurities contained in diamonds. According to the area and volume, quantity, location, color depth and the degree of influence on diamonds, transparency can be divided into: completely clean, internally clean, very slightly defective, very slightly defective, slightly defective and unclean.
4. Cut: If you have a good drill blank, you must have a good driller, otherwise, "if you don't cut the jade, you won't be able to cut it." You should know that the price difference between diamond raw materials and finished products is at least 12 times. Therefore, the cutting of diamonds is an important part of the value of diamonds. Standard cutting should make a diamond present more than 57 facets, and there are strict proportions, standards and angles between different facets. In this way, the light contained in diamonds can be analyzed as much as possible and become the best decoration.
There is a knack for choosing diamond ornaments.
The price of diamonds is mainly determined by 4C standard. If you can understand the pricing principle of 4C standard, you can find the trick and get cheap diamond ornaments.
In the total price of diamonds, weight accounts for 40-60%, clarity accounts for 15-25%, color accounts for 15-20%, and cutting accounts for 20-35%.
Say the weight first. The weight is priced by grades, such as 18-22' is 20', 23'-27' is 25', and 28'-39' is 30', and the price difference of each grade is 3500- 10000 yuan per carat. Therefore, although the price difference between 22' and 23' and 27' and 28' is only 0.0 1 carat, there is a grade difference in price, and the price difference is 350- 1000 yuan. If you choose the weight reasonably, you will save money
There are five grades of clarity, and the clarity difference is 10- 15%, that is, the clarity difference between, VS and SI is 3000-5000 yuan per carat, that is, the clarity of VVS is 300-450 yuan higher than that of 1 VS diamond with the same weight.
(According to national standards, diamond clarity is divided into five categories: LC, VVS, VS, SI and P. In defect description, LC level means that there are no defects inside and outside the diamond under 10 magnification, VVS level means that there are tiny defects under 10 magnification, and VS level means that there are obvious defects under 10 magnification.
Flawless, or FL for short. There are no flaws inside or outside the diamond. Some glitches can also be included in the FL level. This level allows additional facets in the pavilion, but these facets are not visible on the table; Visible natural primary facet or cleavage plane, its size does not exceed the waist width, or does not make the waist round; There are small spots inside, because it is colorless and does not affect the perspective.
Internal cleanliness level (if any). There is no flaw inside, but there is a little flaw on the surface. Very, very subtle internal defect levels (including VVS), very tiny defects, which can only be observed from the exhibition hall, or have very small defects on the surface. The difference between VVS 1 and VVS2 is that the cotton spot of VVS2 is very small, with very small stubble (basically no internal defects).
Very slightly contains VS, referred to as VS 1 or VS2. You can see very tiny flaws, and you can clearly see the size and position. The difference between VS 1 and VS2 is that VS2 may have fine cotton wool and stubble. Slightly contains SI, referred to as SI 1 and SI2. You can clearly see the defects, probably in the center of the table, especially VS2, which is very easy to see.
Inperfect, I 1, I2, I3 for short. You can clearly see the flaws, and sometimes you can clearly see the obvious cleavage.
There is a uniform mark on the cleanliness of diamonds in the world, which is generally marked in the corresponding position of the diamond morphology map of the appraisal certificate. )
Colors are divided into three categories, 1 1 grade, with a difference of 10- 15% between types and 10% between grades. Most diamonds are white (transparent), but there are also pink, green, blue and gold. Generally speaking, the whiter the color, the rarer it is, and the completely transparent and sparkling diamond is the rarest and most expensive. However, colored diamond with high clarity is also very rare and equally valuable. The color grades of diamonds are carefully divided, sorted by English letters from high to low, and the highest is a color. Followed by ABCDEF GHIJK. For example, a VS white diamond of about 3000 yuan, the color accounts for 450 yuan in the price. The same is VS white diamond, the difference between J and H can be 20%, which is the difference 90 yuan. Colorless is the highest grade, numbered100; Close to colorless, yellowish and light yellow 98-75; The following 75 are no longer members of the gem family.
Cutting work accounts for 20-35% of the total price, with 30% as the calculation unit. The benchmark cut price for a 3000-yuan diamond is 900 yuan. Because the quality of cutting affects the degree of "fire" and the size of the ring surface, different cutting workers have certain price differences, with the lowest cutting in Hong Kong and the highest cutting in Belgium. Generally, Belgian cuttings are 25-30% higher than Israeli cuttings, and Israeli cuttings are 15% higher than Indian cuttings. For example, an Indian cut diamond worth 3,000 yuan (900 yuan cut), Israeli cut 1035 yuan, Belgian cut 1290- 1350 yuan. It can be seen that the order from good to bad is: Belgium, Israel, India and Hong Kong.
The measure of tangent is usually expressed by VG (good) or G (good).
Therefore, the price of a 3,000 yuan Indian cut VS white (J-grade) diamond for an Israeli or Belgian cut VS white (H-grade) diamond is about 3,225-3,540 yuan.
Therefore, it is not surprising that yarns with the same clarity and color have a difference of 300-600 yuan between diamonds with different cuts of the same grade. If the definition is higher (VVS level), the difference between color and white is even greater.
The proportion of brands in the price is still uncertain. As China's jewelry industry started late, brand awareness is constantly forming. According to the market survey, the domestic famous brand "Daimengde" is about 1/5- 1/3 higher than the general brand. Therefore, buying diamonds should be decided according to one's own economic ability and purpose (decoration or preservation). Generally speaking, a good brand has good cutting, stable quality and good mosaic technology, but the price is much more expensive.