Certification Labs
Independent gemmological laboratories that identify and grade stones and pearls. The name on the report is what gives it weight.
GIA, IGI, SSEF and Gubelin are the internationally recognised names; SGL and IGL are among those working widely in India.
For pearls, a proper report answers the questions a seller's word cannot: natural or cultured, freshwater or saltwater, treated or untreated.
A report is tied to a specific item, usually by a number laser-inscribed on a stone or recorded with photographs for a pearl.
When you are buying
Check that the report is from a lab with no interest in the sale, and that the item in front of you matches its description and measurements. A certificate for a different pearl is worth nothing at all.
Certificate of Authenticity
A document stating what a pearl is. Useful in proportion to who issued it and what it actually tests.
Valuation
An independent written assessment of what a piece is worth, usually for insurance rather than for sale.
Natural Pearl
A pearl that formed with no human involvement at all. Vanishingly rare, and effectively absent from the retail market.
Assay
The laboratory test that establishes how much gold is actually in a piece.