If it is immanent, the surface is slightly flawed.

VVS 1。 VVS2 contains tiny inclusions (tiny defects invisible to naked eyes).

VS 1。 VS2。 Contains tiny inclusions (tiny defects invisible to the naked eye).

Si1.si2. Small inclusions (invisible to naked eyes)

I1.i2.i3. Inclusions (visible defects)

Second, color.

The color grading of diamonds is divided into 23 grades from English letters D to Z.

D, e and f belong to the colorless range;

G, H, I and J belong to the near colorless range;

K, l and m are yellowish;

Below n is light yellow.

Diamond grading-

Diamonds are known as the "king of gems" in the world because of their highest hardness, crystal clear texture and dazzling features.

It symbolizes success, elegance, loyalty, eternity and innocence, so it is deeply loved by people. Diamonds are the gems in the world at present.

Since the advent of portable detection instruments such as thermal conductivity meter, the most traded gemstones in trade have been used to identify the authenticity of diamonds.

This is a very simple matter, but how to evaluate the quality of a diamond has become the main problem in diamond trade.

The latest national standard GB/T 16554- 1996 "Diamond Classification" stipulates that the factors for evaluating the diamond grade are as follows

There are four, namely, color, clarity, cut and carat weight. These four

Factor is also called "4C" standard, and "4C" is the first letter of four English terms: color, clarity, cut and carat weight.

C, and 4C is an indispensable comprehensive factor to evaluate the quality of a diamond, and it is also a measure for consumers to judge the value of a diamond.

Quasi.

There are all kinds of diamonds in the jewelry market, including pure natural diamonds and irradiated and filled diamonds.

Stone; There are white diamonds (actually colorless, white diamonds on a white background), yellow diamonds and colored diamond, such as

Red, green, blue, orange, etc. ; As far as shapes are concerned, there are standard round diamonds, hearts, ovals and pears.

Diamonds of the same shape. The most common diamond on the market is a white (colorless) standard round diamond, so it is in the "4C" standard.

The classification of color, clarity and carat weight of diamonds only refers to natural white (colorless) to light yellow (brown, gray) series.

Polished diamonds with carat weight greater than 0.2 are classified, while the cut classification is only for standard round cut diamonds or white inlaid diamonds.

(colorless) to light yellow (brown, gray) series, the diamond quality classification is 1 carat ~ 0. 1 carat. The "4C" standard does not apply to colors.

Classification of diamonds, radial diamonds and filled diamonds.

In the "4C" standard, the color of diamonds is divided into 12 grades. The classification method is: pure colorless diamonds are defined as

The highest color pole-extremely white, 100 color, which can be expressed by D or written as D( 100). With the increase of yellow content in diamond,

The color level is gradually reduced to E(99) and F(9

. . . G(97)、H(96)、I(95)、F(94)、K(93)、L(92)、M(9 1)、N(90)

And less than N(90). In the diamond appraisal certificate, the color grade is usually expressed only by English letters. When the color level is lower than n, it is generally

It is considered that the diamond is no longer suitable for cooperative jewelry.