How are diamonds graded for cultivation?

 How are diamonds graded for cultivation？

When purchasing natural diamonds, everyone should have heard of the "4C standard", which evaluates the quality of natural diamonds from four aspects: color, clarity, cut, and quality. What standards are used to grade the quality of cultivating diamonds? Related

When purchasing natural diamonds, everyone should have heard of the "4C standard", which evaluates the quality of natural diamonds from four aspects: color, clarity, cut, and quality. What standards are used to grade the quality of cultivating diamonds? Is there a relevant grading standard for cultivating diamonds that can be referred to? How does the laboratory issue a grading report for cultivating diamonds?

Do you understand the 4C standard?

According to the national standard GB/T 16554-2017 "Diamond Classification", natural diamonds are classified from four aspects: color, clarity, cut, and quality, abbreviated as 4C classification.

Color level:

Divided into 12 levels: D, E, F, G, H, I, J, K, L, M, N,<N.

Cleanliness level:

It is divided into five major levels: LC, VVS, VS, SI, and P, and further subdivided into eleven sub levels: FL, IF, VVS, VVS2, VS1, VS2, SI1, SI2, P1, P2, and P3.

Cutting level:

It is divided into five levels: Excellent (EX), Very Good (VG), Good (G), Fair (F), and Poor (P).

Quality unit:

The unit of mass for diamonds is grams (g). In diamond trade, "carat (ct)" can still be used as the unit of carat weight. 1.0000g=5.00ct.

Cultivate diamond grading standards

The national standards for cultivating diamond grading have not yet been introduced, and relevant enterprise and group standards have been successively released within the industry.

Table 1 Standards for Cultivating Diamond Enterprises and Group Standards

Note: "T" in the name represents the group standard, and "Q" represents the enterprise standard.

As shown in Table 1, some cultivated diamond industry standards and group standards basically refer to the 4C grading system of natural diamonds. In December 2018, Shenzhen Guoshou Gold and Silver Jewelry Testing Center Co., Ltd. launched the Q/NFTC001-2018 "Identification and Grading of Cultivated Diamonds", which distinguishes colors into 8 levels: D, E, F, G, H, I, J, and K; The cleanliness is divided into four major levels: LC, VVS, VS, and SI, and is further divided into eight minor levels: FL, IF, VVS1, VVS2, VS1, VS2, SI1, and SI2. The cutting grading and quality standards are consistent with natural diamonds.

March 2019