1, GIA Diamond Identification Center

Gia is the most authoritative diamond appraisal institution in the world, and now it is the maker of diamond 4C standard. Gia certification, as a non-profit organization, is famous for its impartiality, which is recognized by people inside and outside the industry and can be regarded as the identification of diamonds.

Generally, more than 30% diamonds in China are equipped with gia diamond certificates. However, due to the high appraisal cost of gia diamond certificate, diamonds with gia certificate are more expensive.

2.HRD Diamond Identification Center

HRD is a Belgian diamond appraisal certificate, which is also officially recognized by Belgium and is one of the most authoritative diamond appraisal certificates in the world. HRD diamond color certificate focuses on the detailed characteristics that determine the value of colored diamond, such as color description, color design and luminescence. It plays an important role in detecting whether diamonds are natural colored diamond or imitation diamonds.

3.NGTC Diamond Appraisal Center

NGTC is also the national jewelry and jade quality center. There is no laser coding for bare diamonds and diamond jewelry, and the diamond grading of national inspection is mostly aimed at setting diamond rings. If you buy diamond jewelry instead of loose diamonds, NGTC will be the most convenient diamond certificate authentication center.

The above three kinds are the more authoritative diamond appraisal certificates at present. When consumers buy diamonds or loose diamonds, if they have doubts about the authenticity or grade of diamonds, they can go to these authoritative diamond appraisal institutions for re-appraisal and confirmation.

Extended data

Self-identification method:

1. Because the crystal cell of a diamond is a five-atom tetrahedron, its crystal structure can be regarded as a combination of tetrahedrons connected by angles, which are regularly repeated and arranged in three dimensions. Diamonds composed of tetrahedrons, such as cubic, octahedral and rhombic dodecahedron crystals, have a smooth surface like a mirror, without smooth textures or grooves. Those with smooth texture or grooves are imitations.

2. The hardness of the real drill is extremely high, 10. You can observe the waist of the diamond. If the waist is frosted, this method is most suitable. Because diamond is harder than any imitation, there will be no fine lines like imitation, and the waist of diamond is granular.

3. Similarly, because diamonds are harder than imitations, the faceted edges of imitations are often duller than diamonds, and the faceted edges of diamonds must be sharp.

4. Based on the principle that diamonds are harder than imitations, the faceted edges of imitations are often worn.

5. If a diamond has a natural surface, there is a chance to find a unique "triangular growth line" on the natural surface.

6. If the diamond is broken, its appearance is usually stepped, while the imitation will be completely bent or shell-shaped.

References:

Baidu Encyclopedia: Diamond Identification