Provenance
How We Grade
Nearly every emerald on earth has been oiled. That is normal and accepted — hiding it is not. US sellers are required to disclose clarity enhancement, and most of the trade does it quietly, in the footnotes. We put it in the product title.
| Stage | What happens |
|---|---|
| 01 — Bought in Bogotá | Purchased against an export invoice from registered sellers, never cash across a table. |
| 02 — Graded before listing | Weight, dimensions, colour and oil grade recorded in daylight-balanced light, with the loupe photo taken the same day. |
| 03 — Reported over 1 carat | Stones above 1.00 ct ship with an independent laboratory report naming origin and enhancement. |
| 04 — Returnable for 14 days | If an independent lab grades a stone lower than we did, the return ships at our cost. |
Questions buyers actually ask
Straight answers about oil, origin and certification — the three things that decide what an emerald is worth. If a seller will not answer these, that is your answer.
Are Colombian emeralds treated?
Almost all of them are. Emeralds form with natural fissures reaching the surface, and the trade has filled those fissures with cedar oil for centuries to make them less visible. Treatment is normal and accepted. Failing to disclose it is not.
What does “minor oil” mean on an emerald?
It is a grade of clarity enhancement. Laboratories use a scale — none, insignificant, minor, moderate, significant — describing how much filler sits in the stone’s fissures. Minor means a small amount, visible under magnification but not obvious to the eye.
Does oil make an emerald worth less?
At the same colour, clarity and size, less oil means more value. An untreated Colombian emerald of good colour is genuinely rare and prices accordingly. A heavily oiled stone is not fake — it is simply worth less, and it should cost less.
Can the oil come out of an emerald?
Yes. Ultrasonic cleaners, steam, heat and solvents can strip the filler, and the fissures then become more visible than when you bought the stone. This is why an oiled emerald should never go in an ultrasonic cleaner, and why a closed bezel protects one better than an open setting.
Do I need a laboratory report?
For anything over roughly one carat, yes. A report from an independent laboratory such as GIA or AGL names the origin and the degree of clarity enhancement — the two facts that set the price. Without them you are trusting the seller’s word on both.
How do I tell a real emerald from glass or a synthetic?
Natural emeralds carry irregular inclusions and uneven colour zoning. Glass-filled stones show flash effects along the fractures when you rock them under light, and lab-grown emeralds are often suspiciously clean for the price. A loupe narrows it down; only a laboratory is definitive.
Which Colombian mine produces the best emeralds?
Muzo is the historic benchmark for warm, saturated green. Chivor tends bluish. Coscuez runs lighter and more included, and La Pita has produced fine material since the 1990s. Mine name is a quality signal, not a guarantee — a poor Muzo stone is worse than a fine Coscuez one.
Related: emerald certification · how to read an emerald · loose stones with the oil grade listed
The obligation
Disclosure is not a courtesy we extend — it is required, and most of the trade does the minimum
Under the US Federal Trade Commission’s Jewelry Guides, a seller must disclose gemstone treatments that are not permanent, that create special care requirements, or that significantly affect value. Emerald fracture filling triggers all three of those conditions at once — the oil can dry or seep, the stone must never go near an ultrasonic cleaner, and the degree of filling moves the price materially.
So disclosure is the floor, not the ceiling, and the interesting question is never whether a seller discloses but where. A footnote on a terms page is technically compliant and practically useless to a buyer comparing two stones. Our position is that the grade belongs on the item, in the same size type as the price.
Which gives you a sharp test for any seller, us included: can you find the enhancement grade without scrolling, clicking or asking? If it takes work to find, someone decided it should.
What we refuse to say
The negative disclosures
Most disclosure policies list what a seller promises to tell you. This is the other half — the claims we will not make, because we would not be able to back them.
| We will never write | Because |
|---|---|
| “No treatment detected” on a stone we have not had tested | Untested is not untreated. This is the most common quiet misrepresentation in the business and it works precisely because it sounds like a laboratory finding. |
| A mine name as a fact, without a report behind it | Individual mine attribution is a laboratory judgement, and a contestable one. Where it is our assessment, the listing says our assessment. See why that matters. |
| “Investment grade” or any implied return | We sell physical goods. We are not advisers, nothing here is investment advice, and a gemstone dealer forecasting your returns is a warning sign wherever you meet one. |
| An appraisal value alongside our own price | The trick where a stone is sold at $2,000 with a $6,000 “appraisal” attached. Valuation is a separate service from a qualified independent appraiser, usually for insurance, and it is not ours to assert. |
| A lower value on your customs declaration | It voids your insurance and puts a false declaration in your name. We refuse however politely we are asked — the full reasoning. |
| “Certified” with no laboratory named | The word carries no meaning on its own. Which laboratory, and what did it actually examine? The labs that carry weight. |
Chain of custody
Where the stones come from, documented
Provenance is not only about what is in the stone. It is also about how it reached you, and that matters both ethically and practically — a stone with no paper trail is harder to insure, harder to resell and impossible to verify.
- Purchased against export documentation from registered sellers, never cash across a table. That single discipline is what makes everything downstream possible.
- Lawful export and import with correct classification and accurate declared value in both directions.
- Serialised on arrival — the serial stays with the stone through grading, listing, invoice, any laboratory report and any future enquiry, so we can always tell you what we sold and when.
- Graded in daylight-balanced light before listing, with the loupe photograph taken the same day, so what you see is the stone and not the lamp.
At trade volumes this stops being good practice and becomes regulation — anti-money-laundering obligations, counterparty verification and sanctions screening all apply to dealers in precious stones. We describe ours openly at trade parcels. A counterparty who cannot describe theirs is telling you something.