How Gemstone Certification Works: Reading a Lab Report

What a report confirms

A laboratory report identifies the species and variety (for example 'natural corundum — sapphire'), states whether the stone is natural or laboratory-grown, and records weight, measurements, shape and cutting style.

It also records detectable treatments. For corundum the key line is heat: 'no indications of heating' or 'indications of heating'. For emerald it is the degree of clarity enhancement, graded from none to significant.

Origin opinions

Several laboratories offer a geographic origin opinion as an additional service. Origin is a scientific opinion based on inclusions and trace-element chemistry — it is not always determinable, and origin alone is not a guarantee of quality. When a report gives no origin, we say so on the product page.

What a report does not do

Most coloured-stone reports do not assign a price or an overall quality grade, and a report describes the stone on the day it was examined. Always match the report number, weight and dimensions to the stone you receive.

Which laboratory?

GIA, GRS, SSEF and Gübelin are the references for high-value corundum, spinel and emerald. IGI is widely used for commercial-quality stones. For stones without an external report we provide our own gemological description, and can send the stone to a laboratory of your choice before shipping.

How we disclose it

Every product page lists the laboratory, the treatment finding and the origin exactly as reported. If a stone has no external report, the certificate field reads 'TopGemstoneHub gemological description' rather than a laboratory name.