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Second, the grade of diamonds:

The grade of diamonds is 4C.

1, weight (Caratage, identification mark is CT), needless to say, of course, the heavier the better. 1CT is equal to 100 point.

2, Color (color), there is a general standard in the world, starting from D, basically up to Z, below Z is generally considered as industrial diamond, which is often called diamond.

3. Clarity is commonly used internationally to indicate IF, VVS, VS, SI, i:

1, IF is flawless, so you can't see any flaws under a ten-fold magnifying glass.

2.VVS is subdivided into VVS 1 and VVS2, both of which are extremely slight defects, that is, it is extremely difficult to see that the defect is VVS 1 and the defect is VVS2 under a magnifying glass of ten times.

3.VS is subdivided into VS 1 and VS2, all of which are micro-flaws. Under the magnifying glass of ten times, it is difficult to see that the defect is VS 1, but it is easier to see that the defect is VS2.

4.SI is subdivided into SI 1 and SI2, all of which are minor flaws. SI 1 and SI2 can be easily seen under a magnifying glass of ten times.

5.I is subdivided into I 1, I2 and I3, all of which are visible to the naked eye. Visible defects are I 1, I2 and I3.

4. Cut is the only artificial control. Divided into five major items:

The optimum ratio is 1, the depth ratio (depth) is 59.3 ~ 6 1.0%, and the optimum ratio is within 52.5~67%.

2. The aspect ratio is 53.0 ~ 6 1.0%, preferably within 5 1~70%.

3. The waist seal is medium good, thin and slightly thick, very thin and extremely thick, and extremely thin, extremely thick and extremely thick.

4.Culet is sharp, minimal (none), minimal (middle), slightly larger (lager), large (lager), extremely large (lager) and extremely large (lager). If the skirt surface is too small, it is also easy to wear.

5. Fish can be divided into polished and symmetrical, excellent, very good, good, average to good, average and poor.

Third, the misunderstanding when purchasing:

There are two main points:

1, color: many merchants say that the color they drill is white, and the concept of white can be called white as long as it is above H, but there are five grades from D to H, so this merchant will not introduce it voluntarily, because if the other 3C are the same, of course, D color white is the most expensive, H color white is the cheapest, and the difference between them is abnormal, D and E are extremely white, F and G are excellent white, and H is white.

2. Cutting: If you ask sales: "What is eight arrows and eight hearts cutting?" He would say, "This is the latest Cupid perfect cut." In fact, in the vernacular, eight arrows and eight hearts are not cutting work, but turning work. There are many shapes of diamonds, round diamonds are the most popular and common in China, followed by princess, pear-shaped and heart-shaped, all of which have their own characteristics. After hundreds of years of development, every shape has formed a variety of lathes. Take the round drill as an example, the most common lathes are 58-sided lathes and the latest popular Cupid eight-arrow eight-center lathes. A good lathe must cooperate with good cutting. For example, a lathe with eight arrows and eight centers can only display eight congruent arrows and centers when cutting with double EX. Without double EX cut, eight arrows cannot be congruent. At this time, the drill bit glowed in the sun.

3. Bracket: A good diamond is a good bracket. In terms of materials, the purity is too soft, such as 24K gold, PT990, PT950 and so on. And the bracket will be deformed if it is not taken for too long. As far as stents are concerned, the significance of show is greater than the actual significance. Generally speaking, diamonds below 50 cents only need 14K platinum, diamonds below 10CT need 18K platinum, and diamonds above 1CT need PT750. The color of the new PD palladium is also good, but the market price is about half that of PT platinum. As long as it is not used to pretend to be PT, it is also a good choice as long as you like it.

Fourth, about the value of diamonds:

Many people tend to consider preserving their value when buying diamonds. In fact, as a diamond, the annual output is still considerable, and only large particles have the value of preserving value. According to international practice, only diamonds above 1CT have the basic conditions for preserving value, but even 3C excellent 1CT diamonds are difficult to sell at a high price in the auction, because the output of 1CT diamonds is quite stable. The most direct performance of a product's value preservation comes from its average transaction price in the second-hand market.

Five, how to choose the right diamond:

As an ordinary consumer, tens of thousands of diamonds above 1CT are unbearable, so there is no need to pay special attention to the 4C of diamonds when purchasing. A more intuitive way is to look at the overall shape. The bare diamonds above 1CT are like a one-man show, which can reflect its own value, while the diamonds below 1CT, which are most concerned, are more like sketches and need to be made together. The conventional choice is that the bracket design can make the diamond look bigger, brighter and more beautiful. It should be emphasized that there are four claws and six claws that are popular at present. This inlay method was initiated by Tiffany, and we usually call it Tiffany's point inlay method or crown inlay method. As one of the top four jewelers in the world, the diamond it chooses can show its own value, so the design essence of this bracket is actually to reduce the mask that the bracket shows its own value to the diamond as much as possible, so that it can show its own value more strongly. So this kind of bracket is often used to hold the diamond very high. If you want to choose this kind of shelf, the 4C of the diamond is very important. If you don't have more than 50 points of diamonds, the other 3C is also quite good, so it's best not to choose this bracket.

Remarks on intransitive verbs:

1. Internationally, no grade certificate is issued for diamonds with a score below 20. The attached certificate only proves the authenticity of the diamond.

2. Common international certificates are GIA in the United States and HRD in Europe. In terms of clarity, GIA's IF is equivalent to HRD's LC, and I is equivalent to P.

There are too many national and municipal appraisal institutions in China. Recommend old-fashioned jewelry houses such as Old Temple and Old Fengxiang. Although Tongji University, Shanghai University and many other universities are also above the municipal level, they are not directly facing consumers after all.

4. All the above are white diamonds. In addition to white diamonds, pink diamond, yellow diamonds, blue diamonds, green diamonds, black diamonds and champagne diamonds are common, collectively known as colored diamond. They have their own scoring method on color. Fancy bright yellow is the best color for yellow diamonds. Fancy light yellow and fancy thick yellow are common. Some lawless elements will take advantage of the fact that only a few people in China know about colored diamond, pretending to be champagne diamonds and yellow diamonds. Earn huge profits. When buying colored diamond, consumers must pay attention not to buy things they don't know, especially the price, in informal shops.

5. The main diamond cutting and grinding centers in the world are Antwerp, new york, Mumbai and Tel Aviv.

6. World-class appraisers: Gemological Institute of America (GIA), Gemological Institute of Europe (EGL), Diamond High Council of Belgium (HRD), Gemological Society of America (AGS) and International Gemological Institute (IGI), among which GIA of America and HRD of Europe are the most famous.