The uncharacteristic absorption spectrum means that the identified gem shows a characteristic pattern of absorption bands or lines in the visible spectrum, and its complete pattern is also the "absorption spectrum". There are many gems and diamonds in nature that do not have absorption spectrum characteristics. This does not mean that the thing identified is fake.

A jewelry appraisal certificate is a credible certification of the authenticity and attributes of rare precious metals, gemstones, or finished jewelry. It is implemented by professional institutions and professionals who are qualified for appraisal. If the appraisal certificate is issued by a professional organization, it is generally genuine.

Extended information:

The gem identification certificate contains the following contents:

1. Certificate number

It is non-repeatable and the testing unit You can use it to find deposits.

2. Photos, shape, color, transparency, weight and size, etc.

They not only describe the basic situation of the sample being tested, but also have the significance of calibrating the sample to prevent the certificate from being Zhang Guan Li Dai. If someone is using it to impersonate, they can be identified through this data.

3. Refractive index, optical properties, gloss, relative density, fluorescence characteristics, microscopic observation results, etc.

This is the main basis used to confirm what the sample being tested is. If there is no such data, or only one or two items, the reliability of the conclusions drawn is questionable. In addition, they should be actual measured results, not theoretical values ??or guesswork.

4. Appraisal results

According to the provisions of my country’s promulgated jewelry and jade standard GB/T 16552-2003 "Jewelry and Jade Name", if the sample is a natural gemstone without any treatment, . Only then can the name of the gemstone be directly written;

If it is a synthetic gemstone, it must be stated as XX synthetic gemstone; if it is an untreated gemstone, the gemstone that has been optimized can still be written directly as XX gemstone. If the name belongs to treatment, the word treatment should be added in brackets after the name of the gemstone, and the treatment method should also be written in the remarks.

5. The signatures and identification dates of the tester and inspector, as well as the official seal of the testing unit. This is the basis for the legitimacy of the certificate.

Baidu Encyclopedia - Absorption Spectrum

Baidu Encyclopedia - Gemstone Appraisal Certificate