The certificate is the part of the purchase people look at least and rely on most. It is the document you will reach for if you ever insure the piece, inherit it, sell it, or simply want to know what you own. It is worth learning to read before you need it.
Store certificate and laboratory report
These are two different documents and both are legitimate.
The store certificate is the establishment’s formal statement about what it sold you: which stone, which metal, what weight, what treatment. Its value lies in the fact that it commits whoever signs it.
The gemological laboratory report is issued by an independent third party that examines the stone with instruments. It does not say what the stone is worth or who owns it: it says what it is. It is justified mainly on higher-value stones.
Neither replaces the other. Every piece should leave with the first. The second appears when the stone warrants it.
The fields to look for
- Species identification. It should say natural emerald. If it says synthetic, lab-created or hydrothermal, the stone was manufactured: entirely legal to sell, and in a completely different price bracket.
- Carat weight. One carat is 0.2 grams. In pieces set with several stones, the total weight and the weight of the principal stone are usually listed separately. Make sure you know which number you are reading.
- Treatment. The single most important line. See below.
- Metal and purity. 18k, 14k, silver — stated, not implied.
- Measurements and cut. Dimensions in millimeters identify the stone later. Two emeralds of the same weight can look very different.
- Date, and the signature of whoever issues it. A certificate nobody signs commits nobody.
The treatment line
Almost all emeralds on the market are oiled to improve the appearance of surface-reaching fissures. This is an accepted, centuries-old practice. What matters is that it is declared, and with what degree: none, minor, moderate, significant.
If the certificate does not mention treatment at all, the document is incomplete. That is not a technicality. An undeclared treatment is the most common way a buyer overpays.
What a certificate does not do
It does not set a market value, it does not prove the mine of origin, and it is not an appraisal for insurance purposes. Those are separate documents, issued by different people, and any store that conflates them is doing you no favors.
Would you rather settle it in person, with the stones in front of you? We are in the Edificio Pombo, open every day from 10:00 am to 7:00 pm.
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