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Gems certificate

I need to know what informations cannot be missing from a gem certificate.
Can someone help me?

-Name of the Lab. With informations to authenticate the certificate as website, e-mail, address and phone #.
-Certificate number.
-Date .
-Gem identification.
-The 4C
-Size in mms
Some labs show disclosures as:
. Uses
. Instruments used.
. Etc.
In case of diamonds include the charts for colors, clarity diagrams.
Good luck.

Thank you Very much

It depends on what gem you are having a report done on, Colored Gem or Diamond and if a colored gem what type of colored gem and if a diamond what the clarity or treatments might be. GIA when doing a colored gem report does not give a clarity grade. Except for Emerald, Corundum, spinel and Alexandrite does not give an origin and typically will only give an origin if and additional fee is paid. On colored gems no cut grade is given that is only a Diamond grade. Natural Diamonds that are not drilled and filled nor a clarity of I3or clarity enhanced will get clarity grades, inclusion chart, cut grades and so forth. As for treatments those treatments that can be distinguished from natural occurrences will be listed, however, for treatments that are indistinguishable from natural occurrences such as Radiation for tourmaline, some thermal treatments such as those in Tanzanite & some corundum will read as follows;
Many gemstones are routinely treated by different methods to improve the color or appearance. In some cases, treatments like heating and irradiation cannot be detected.
Heat Treatment
A wide range of gem materials may be subjected to low temperature heat treatment to improve or change the color of the stone. It is also possible for this heating process to occur naturally when the gemstone is in the earth. To determine if the heating was done by man (as a treatment) vs. heating by nature may be difficult if not impossible.
Some gem materials may be subjected to irradiation to improve or change the color of the stone. Generally, there is no residual radioactivity left in such stones. These same gemstones may be naturally irradiated in the earth over a long period of time. To determine if the irradiation was done by man—as a treatment—or by nature is usually not possible with today’s testing methods.
I hope this clears up some things and while it is not an all inclusive list I hope it gets the point across regarding treatments and what can and cannot be determined.