There is a reason this question comes up more than it used to. The mine closed, supply is finite, prices reflect that, and where scarcity and money meet you find people describing stones more generously than they should.
The good news is that a genuine Argyle pink diamond is one of the most thoroughly documented objects in the jewellery trade. There is a paper trail, there is a number laser etched into the stone itself, and there is a register you can check it against.
Here is how to work through it properly.
Three Separate Questions
People collapse these into one, which is where confusion starts. Verification means answering three distinct things.
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Is it a natural diamond, rather than laboratory grown or a simulant.
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Is the colour natural, rather than induced by treatment.
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Is it from Argyle, rather than a pink diamond from somewhere else.
A stone can pass the first two and fail the third. It will still be a lovely natural pink diamond. It will not carry the premium that Argyle provenance commands, and the difference is substantial.
Why Verification Matters Now
The Argyle mine delivered its final production in November 2020, having supplied the large majority of the world's pink diamonds across thirty seven years.
Nothing new is coming. Every Argyle pink that will ever exist already exists, and everything now traded moves through the secondary market. That is precisely the environment in which documentation stops being a formality and starts being the asset.
Our page on the history of Argyle covers how the mine came to occupy that position.
The Argyle Certificate And Lot Number
This is the strongest form of proof available, and it has a specific starting point.
From January 2005 onwards, qualifying Argyle stones were laser inscribed with a unique lot number and issued an Argyle Pink Diamonds Gem Identification and Authenticity Document. The document travels with the stone, and the number is the link between the paper and the object.
Checking It Against The Register
Here is the part most buyers do not realise they can do. That lot number is recorded, and the Diamond Check Service lets it be searched so a laser inscribed stone can be verified against the record.
A seller offering a genuine certified stone will have no difficulty with you checking. Reluctance at this point is itself information.
Stones From Before 2005
Not every genuine Argyle pink has this documentation, because the inscription and certificate programme began in 2005. Older stones, and stones removed from earlier jewellery, may be entirely genuine with no Argyle paperwork at all.
That does not make them fake. It does mean provenance has to be established another way, usually through independent laboratory analysis and whatever ownership history exists. Price should reflect that difference in certainty.
Certified By Argyle Or Argyle Origin
Two phrases that sound almost identical and are not, and the gap between them is money.
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Certified by Argyle |
Argyle origin |
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Graded for colour and clarity by Argyle |
Graded by an independent laboratory |
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Laser inscribed with an Argyle lot number |
May carry a different inscription, or none |
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Issued an Argyle authenticity document |
Carries a laboratory report instead |
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Verifiable against the Argyle record |
Provenance rests on the seller and the lab |
Neither description is dishonest, and an Argyle origin stone genuinely came from the mine. But they are not interchangeable and they do not carry the same price. A seller who uses the phrases loosely is telling you something about how carefully they work.
The Laser Inscription
The inscription is the physical half of the verification, and it is routinely misunderstood.
Where It Is And What To Expect
Laser inscriptions are applied to the girdle of the stone, the narrow band around its widest point. They are microscopic and are not visible to the naked eye. Reading one normally requires ten times magnification or more.
A jeweller will have a loupe or microscope and can show you. If a stone is already set, the inscription may be partly obscured by the setting, which is normal rather than suspicious.
The Thing That Panics People
Worth knowing because it comes up constantly. Modern phone cameras focus very close and magnify considerably, so people photograph their own ring, spot the inscription, and assume something is wrong with the stone.
Nothing is wrong. It is more pronounced in step cuts such as emerald and Asscher, where the large open facets act like mirrors and can bounce the inscribed area into view from the top. You may catch a faint dark line without magnification. What you should not be able to do is read the characters.
What An Inscription Does Not Prove
An inscription is a reference, not an authentication in itself. It is only as good as the record it points to, which is exactly why checking it against the register matters.
Note also that laboratory grown diamonds must be clearly disclosed as such, and laboratory grown stones commonly carry inscriptions of their own. An inscribed number by itself tells you a laboratory examined the stone. It does not tell you what the laboratory concluded.
Whether a stone is individually inscribed at all varies with size and with the laboratory, and very small stones are frequently not inscribed individually.
Reading The Argyle Colour Scale
Argyle used its own grading language, which looks cryptic until someone explains it.
The hue is given as a letter code. PP is purplish pink, P is pink, PR is pink rosé, and PC is pink champagne. A number from 1 to 9 indicates intensity, and it runs the opposite way to intuition, with 1 being the most intense and 9 the lightest.
So a stone described as 1PP is an intensely saturated purplish pink, and sits at the very top of the scale. A 6P is a considerably lighter pink. The difference in value across that range is enormous, which is why the code is worth learning before you negotiate.
Our Argyle buying guide works through what those grades mean in practice.
Independent Laboratory Verification
Argyle documentation answers the provenance question. An independent laboratory answers the other two, and for a stone without Argyle paperwork it does most of the work.
Coloured diamond reports state whether the origin of colour is natural or treated alongside the fancy colour grade, which is the single most important line on the document.
Laboratories distinguish natural colour from treated using spectroscopic analysis, including ultraviolet, visible and infrared spectroscopy along with photoluminescence and other techniques. Colour induced by irradiation or high pressure high temperature treatment leaves signatures that these methods detect.
There is a further point specific to pinks. The colour arises from plastic deformation of the crystal structure rather than from a chemical impurity, and that deformation can be examined directly using crossed polarisers and imaging techniques. It is part of how a natural pink is confirmed.
Since the closure, IGI has provided certification for Argyle origin pink diamonds moving through the secondary market, which gives a route to documentation for stones without an original Argyle certificate.
Tender Stones
A small category worth recognising, because it sits at the very top of the market.
The Argyle Pink Diamonds Tender was an annual invitation only sale of the finest stones the mine produced each year, offered to a small group of invited buyers with catalogue documentation for each stone.
Tender stones are individually named and recorded, and their documentation is correspondingly detailed. If a stone is described as a tender stone, that claim is specific and checkable, so ask for the year and the name.
Red Flags
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No documentation and no explanation. A genuine pre 2005 stone has a story. Silence is different.
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A photocopy rather than the original document. Ask why.
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Reluctance to let you check the lot number against the register.
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The phrases used loosely, with Argyle certified and Argyle origin treated as the same thing.
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A price well below the market for the stated grade. Rare things are not cheap by accident.
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Colour described in vague language rather than the Argyle code or a laboratory fancy colour grade.
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Pressure to decide quickly. Nothing about this purchase is urgent.
What To Ask Before You Buy
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Is it certified by Argyle or Argyle origin, and may I see the document.
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What is the lot number, and can we check it against the record together.
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May I see the inscription under magnification.
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What is the Argyle colour code, or the laboratory fancy colour grade.
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Which laboratory issued any independent report, and does it confirm natural colour origin.
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What is the ownership history, particularly for a stone without Argyle paperwork.
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Will you put the description in writing on the invoice.
That last one matters more than people think. A written description on an invoice is what you rely on if the stone is ever misrepresented.
What To Do Next
If you are considering a purchase, bring the paperwork to someone who handles these stones regularly and have it examined properly before you commit.
Our overview of Argyle pink diamonds covers the wider picture, and our Argyle Select Atelier status reflects the relationship we hold with these stones.
When you want to look at verified stones with their documentation in front of you, our loose Argyle pink diamonds are where that conversation happens.
The Short Version
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Verification answers three questions, being natural diamond, natural colour, and Argyle origin.
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From January 2005 qualifying Argyle stones carry a laser inscribed lot number and an authenticity document.
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That lot number can be checked against the Argyle record, so ask to check it.
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Genuine stones predating 2005 may have no Argyle paperwork, which is not the same as being fake.
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Certified by Argyle and Argyle origin are different claims at different prices.
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Inscriptions sit on the girdle, are microscopic, and need magnification to read.
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Seeing a faint line through your phone camera is normal, especially in step cuts.
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An inscription is a reference, not proof, and laboratory grown stones carry them too.
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The Argyle code runs PP, P, PR and PC for hue, with 1 the most intense and 9 the lightest.
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An independent report confirming natural colour origin is essential where Argyle paperwork is absent.
Buy the documentation as carefully as you buy the stone, because with something this rare the paperwork is a meaningful part of what you own.
