Reports and certificates for colored gemstones differ in appearance depending on the issuing laboratory or institute.

In any case, a certificate must contain:

• Name of the issuing institute
• Certificate number
• A photo of the gemstone
• The stone’s dimensions, including its weight, to the nearest hundredth of a millimeter or hundredth of a carat (some institutes use the nearest thousandth of a carat.)
• The mineral, e.g., corundum or beryl
• The name of the gemstone , e.g., “ruby”
• A statement indicating whether it is a natural gemstone or a synthesis
• The color of the stone. For a ruby, “red” is derived from the gemstone itself. For a sapphire, the color needs to be specified.
• A statement about whether the stone is naturally colored, untreated or heat-treated.
• A statement as to whether the stone has been otherwise treated or enhanced (e.g., fracture-filled, impregnated, irradiated, or diffused)
• Optional: The geological origin of the gemstone.

Origin reports to confirm the geographic origin of a stone must be ordered separately by the owner.
For some stones, determining the origin makes no difference to the value: almost all intense yellow sapphires come from Sri Lanka.

It’s quite different with rubies, though. Since rubies from Burma fetch higher prices, determining the origin is essential.

The following special remarks about the color can be found in certificates for rubies:

• “Pigeon’s blood”: The most expensive color, it is only given to natural colored rubies and substantially increases the price.
• “Intense/vivid red”: this is a gradation to “pigeon blood” and also increases the price.

For blue sapphires, there are two internationally sought-after color grades:

• “Royal blue”: This designation, given to a dark blue with high saturation and brilliance, is the most sought after and valuable.
• “Cornflower blue”: This color grade is also highly valuable. It describes a very pure blue.

The cost of a certificate ranges from around 30 euros at a local institute in countries like India or Sri Lanka to several thousand euros for high-quality, rare gemstones. Thus, the purchase price of the gemstone also influences the type of certificate received when buying a stone. For example, if the stone costs 500 euros, the buyer cannot expect an SSEF or GRS certificate.

The two primary laboratories that certify diamonds are the Gemological Institute of America (GIA) and the HRD. Certificates from other labs may lead to significant price reductions when reselling.

In the past, certified diamonds were sealed in plastic boxes. The certification number was on the plastic box, linking the diamond to the certificate. Today, this method is outdated. Now, the certificate number is laser-inscribed on the girdle of the diamond (the thin outer edge) in letters no larger than a few micrometers, making it invisible to the naked eye. This establishes the connection between the diamond and the certificate.

To check if the certificate is genuine, enter the certificate number on the certifying institute’s website to receive a scan of the certificate. (Of course, ownership data is not public.)

A diamond certificate is considered part of the proof of ownership. In any case, certificates should be kept separate from gemstones.

Here is a note about the types of GIA diamond certificates: If the diamond weighs more than one carat, the “GIA Diamond Grading Report” (8.5 x 3.7 inches) is enclosed. If the diamond weighs less than one carat, the “GIA Diamond Dossier” measures 12.8 by 9.3 centimeters.

The contents are indicated in the diamond certificate:

• Certificate number
• Cut (brilliant, emerald, oval or princess cut, etc.)
• Diamond dimension to the nearest hundredth of a millimeter
• Weight in carats to the nearest hundredth of a carat
• Color grade from D to Z
• Clarity grade from FL to P3
• Cut grade from “excellent” to “poor”
• Polish from “excellent” to “poor”
• Symmetry from “excellent” to “poor”
• Fluorescence ranges from “none” to “strong”
• Other characteristics of the diamond
• A profile of the cut
• For diamonds heavier than one carat, a schematic representation of the inclusions is also provided, if applicable.

Most certificates omit a photo of a white diamond because it would not provide much information; the above parameters are more important.

Usually, all white diamonds of good quality weighing 0.33 carats or more are certified. If the weight is less than that and the buyer wants a certificate, they will be charged separately for it.

For colored “fancy diamonds,” the color is not mentioned on the D-Z scale, but rather, the corresponding color designations are used (e.g., “fancy intense yellow”). All other information remains the same. GIA certificates for colored diamonds (GIA Colored Diamond Identification and Origin Report) are always 21.6 x 9.3 cm.