DIAMOND IDENTITY:
read the report in order

A natural diamond crystallised through geological processes.

A laboratory-grown diamond crystallised through a controlled manufacturing process.

The finished materials can be difficult or impossible to distinguish by eye.

GIA says that natural and laboratory-grown diamonds can be separated through differences created by their growth environments: atomic-scale defects, impurity patterns, growth structures, fluorescence and spectroscopic characteristics.

That means a loupe is not a reliable natural-versus-laboratory-grown test for an otherwise convincing modern stone.

The report conclusion should be treated as a laboratory identification result, not as something the buyer is expected to recreate from photographs.

For the collector file, use a dedicated field:

Growth origin: Natural diamond

or:

Growth origin: Laboratory-grown diamond

Do not use:

Real diamond: Yes

That language is too vague to carry the distinction.

Once the report identifies a laboratory-grown diamond, a second question can appear:

How was it grown?

The two principal commercial methods are:

HPHT — High Pressure, High Temperature

and:

CVD — Chemical Vapour Deposition.

They both produce diamond.

They do it differently.

HPHT growth

GIA describes HPHT growth as using very high pressures and temperatures, with carbon crystallising around a diamond seed in a press.

The method recreates some of the physical conditions associated with natural diamond formation, but in a controlled manufacturing environment and on a radically compressed timescale.

CVD growth

Chemical Vapour Deposition operates at much lower pressure.

A carbon-containing gas is activated into a plasma, and carbon is deposited layer by layer onto diamond seed material.

The resulting growth structure is different enough that a laboratory can distinguish it from HPHT production and from natural growth.

The important collector point is not which acronym sounds more advanced.

It is that growth method is not the same thing as treatment.

This is one of the most important pieces of vocabulary in the entire subject.

HPHT can be a growth method.

A diamond can be grown by High Pressure, High Temperature synthesis.

But:

HPHT can also be a treatment method.

High pressure and high temperature can be applied to a diamond after it already exists in order to alter colour.

That later processing can be performed on natural diamonds or on some laboratory-grown diamonds.

So a report or catalogue using the letters HPHT needs context.

Ask:

HPHT-grown?

or:

HPHT-treated?

Those are different histories.

A diamond described only as “HPHT” has not been described precisely enough.

The same mistake appears in another form.

A CVD-grown diamond is a diamond whose crystal was produced by Chemical Vapour Deposition.

That says nothing, by itself, about whether the finished crystal was later treated.

GIA’s research on recent laboratory-grown diamonds reports that post-growth processing is common in CVD production, particularly treatment intended to improve colour.

GIA has documented CVD-grown diamonds subsequently subjected to HPHT processing, irradiation and annealing.

Therefore:

CVD-grown

is a growth conclusion.

CVD-grown, post-growth treated

is a fuller history.

And:

CVD-grown, no indication of post-growth treatment

is different again.

The collector should preserve the complete wording used by the issuing laboratory.

IGI provides useful wording for understanding this distinction.

Its laboratory-grown reporting can identify the growth process and, for untreated examples, use language such as:

“as grown with no indication of post-growth treatment.”

That phrase does not mean the diamond is natural.

It means the laboratory-grown diamond has no indicated later treatment after its laboratory growth.

This is exactly why “natural” and “untreated” cannot share one database field.

A good diamond record has both:

Growth origin

and:

Treatment status.

Natural origin does not mean untouched.

GIA documents several treatments used on natural diamonds.

HPHT processing

Can alter or improve colour in certain natural diamonds.

Irradiation

Can create or modify colour by changing colour centres within the diamond.

Annealing

Heat treatment can be used alone or after irradiation to modify colour.

Laser drilling

A laser can create a channel to reach a dark inclusion, allowing the appearance of the inclusion to be reduced.

These are later interventions on a naturally grown diamond.

The correct description is therefore not:

natural versus treated.

It can be:

natural diamond, treated colour

or:

natural diamond, laser drilled

or:

natural diamond, no indicated treatment

depending on the laboratory result.

Treatment status does not replace growth origin.

It sits beside it.

Not all treatment types are handled the same way by laboratories.

GIA currently says it issues grading reports for diamonds subjected to treatments it regards as stable, including processes such as irradiation, annealing, laser drilling and HPHT colour treatment, with the treatment prominently disclosed.

GIA does not issue grading reports for diamonds with treatments it considers unstable or non-permanent, such as:

• fracture filling;
• surface coating.

That absence can itself become meaningful evidence.

If a seller presents a “GIA graded fracture-filled diamond”, the wording should trigger immediate verification because it conflicts with GIA’s stated report policy.

Do not assume every treatment belongs to the same disclosure system.

A collector reading laboratory-grown diamond reports in 2026 has another problem: the vocabulary can depend on when the report was issued.

On 1 October 2025, GIA changed its reporting system for colourless-to-near-colourless laboratory-grown diamonds.

GIA no longer applies the natural-diamond colour and clarity nomenclature to its current D-to-Z laboratory-grown quality assessment.

Instead, the current GIA Laboratory-Grown Diamond Quality Assessment classifies eligible loose laboratory-grown diamonds as:

Premium

or:

Standard

based on a combined assessment of colour, clarity, polish, symmetry and cut.

A stone falling outside the defined criteria does not receive either designation.

That is a significant reporting change.

An older GIA laboratory-grown diamond report can still show familiar D-to-Z colour and clarity terminology because it was issued under the earlier system.

GIA stated when introducing the change that existing laboratory-grown reports remain valid.

So two genuine GIA documents can use different quality languages simply because they belong to different reporting eras.

The report date matters.

GIA’s current system is not a universal industry format.

IGI’s current 2026 Laboratory Grown Diamond Report still uses individual 4Cs-style fields including carat weight, colour, clarity and cut where applicable.

IGI also says growth method and treatment information may be noted in report comments and continues to identify whether the material is laboratory-grown.

That means a current IGI report and a current GIA report can describe comparable laboratory-grown diamonds using different systems.

This creates a simple rule:

never compare report words without first identifying the laboratory and report format.

“Premium” on a current GIA quality assessment is not an alternative spelling of “D VVS2”.

A D/VVS2 laboratory-grown diamond on an IGI report is not automatically equivalent to every GIA Premium assessment.

They are different reporting systems.

Natural-diamond grading has trained buyers to start with the 4Cs.

That is appropriate only after the material question is settled.

GIA’s current natural Diamond Grading Report provides a full 4Cs assessment for eligible loose natural D-to-Z diamonds, including a plotted clarity diagram. Standard round brilliant diamonds also receive a GIA cut grade.

But colour, clarity, cut and carat do not answer:

• natural or laboratory-grown;
• CVD or HPHT;
• treated or untreated;
• stable or unstable treatment;
• whether the stone matches the document in front of you.

Those are different layers.

A collector should therefore read the report in this order:

1. Material identity

2. Growth origin

3. Growth method, where reported

4. Treatment status

5. Quality assessment

6. Physical reconciliation

7. Price

Starting at colour and clarity is starting in the middle.

Current GIA services for laboratory-grown coloured diamonds explicitly combine several layers in one report.

GIA says its Laboratory-Grown Colored Diamond Report can include:

• a full quality assessment;
• a plotted clarity diagram;
• growth type;
• post-growth treatment.

A related colour-identification format can report:

• colour;
• colour distribution;
• growth type;
• post-growth treatment.

This is exactly the structure collectors should learn to preserve.

One diamond can have:

Growth origin: laboratory-grown.

Growth method: CVD.

Post-growth treatment: detected.

Colour: Fancy Vivid orangy pink.

None of those lines makes another redundant.

Marketing language sometimes makes treatment sound like something performed only on natural material.

GIA research shows otherwise.

Post-growth treatment is part of the modern laboratory-grown diamond landscape.

CVD-grown diamonds in particular may undergo HPHT processing intended to reduce unwanted colour.

Fancy-colour laboratory-grown diamonds can undergo combinations of treatment to create or modify colour.

This does not mean every laboratory-grown diamond is treated.

It means the reporting system has to ask.

That is the point of the treatment field.

A more accurate way to think about the market is:

Simulants sit outside this matrix because they are not diamond.

That table is more useful than dividing a jewellery tray into:

Natural / Lab-Grown / Treated.

The third label overlaps the first two.

GIA laser-inscribes its current laboratory-grown assessed diamonds with an identifying report or assessment number and the term Laboratory-Grown.

That is useful object-level evidence.

It is not infallible.

GIA has repeatedly documented fraud involving laboratory-grown or treated diamonds carrying counterfeit inscriptions linked to genuine GIA natural-diamond reports.

In 2024, GIA announced a same-day verification service after seeing laboratory-grown diamonds deliberately cut to dimensions close to natural diamonds and then given fraudulent GIA report-number inscriptions.

In a 2025 Gems & Gemology laboratory note, GIA documented four stones with counterfeit inscriptions: two were laboratory-grown and two were HPHT-treated natural diamonds rather than the untreated natural stones described by the copied reports.

This changes the collector workflow.

Do not stop at:

The inscription number exists in Report Check.

Ask whether the physical diamond matches the report:

• weight;
• measurements;
• shape;
• cutting style;
• clarity characteristics;
• inscription style;
• other report data.

A valid report number can still be attached fraudulently to the wrong stone.

GIA Report Check is essential.

It allows the user to confirm that a report number corresponds to data held by GIA.

That helps detect fabricated or altered documents.

It does not eliminate the need to reconcile the physical diamond.

The logic is:

Report Check: Is this a real report record?

Physical reconciliation: Is this the diamond described by that report?

Those are separate tests.

For an important transaction, both matter.

Loose-diamond reports offer the laboratory the most direct access to the stone.

Once a diamond is mounted:

• the girdle inscription may be partly hidden;
• exact weight may not be independently measurable;
• some inclusions may be obscured;
• pavilion access can be restricted;
• measurements may be limited.

IGI currently offers reports for finished jewellery containing natural and laboratory-grown diamonds, documenting mounted stones as the setting permits.

GIA’s current D-to-Z laboratory-grown Quality Assessment is specified for loose stones.

Therefore the report attached to a ring can depend partly on when and how the stone was examined.

Record whether the report was issued:

loose

or:

mounted

Do not assume the same scope.

Suppose a laboratory-grown diamond carries a genuine 2024 GIA report with D colour and VVS2 clarity.

In 2026, GIA uses a different D-to-Z lab-grown assessment system.

The correct collector record is not to convert the old report retrospectively into Premium.

Preserve the historic document exactly.

Record:

GIA report, 2024 — D / VVS2 under the reporting system then in force.

If the diamond is submitted later for a new service, keep the new report separately.

A report is evidence created at a date.

Updating the laboratory’s terminology does not rewrite the object’s documentary history.

Collector databases often extract only:

• carat;
• colour;
• clarity;
• cut.

That loses the reporting authority.

With contemporary laboratory-grown diamonds, the omission is especially serious because reporting systems are no longer fully parallel.

Every stored grade should travel with:

laboratory

report type

report number

report date

report version/system where relevant

That allows future readers to interpret the wording correctly.

Without those fields, “D VVS2” becomes contextless data.

For any important diamond, keep the following fields.

Material

Diamond confirmed?

If not, exact simulant or material identification.

Growth origin

Natural.

Laboratory-grown.

Exact laboratory wording.

Growth method

HPHT.

CVD.

Not reported.

Not applicable.

Do not infer from appearance.

Treatment

No indication under report scope.

HPHT treated.

Irradiated.

Annealed.

Laser drilled.

Other laboratory wording.

Unstable treatment / no grading report where applicable.

Quality system

GIA natural 4Cs.

GIA current lab-grown Premium/Standard assessment.

Older GIA LGDR terminology.

IGI laboratory-grown 4Cs.

Other laboratory system.

Do not merge them.

Report

Laboratory.

Report type.

Number.

Date.

Digital/paper format.

Report Check / verification result.

Physical link

Laser inscription.

Weight.

Measurements.

Shape.

Clarity characteristics.

Photographs.

Any discrepancy.

Jewellery context

Loose or mounted when reported.

Setting.

Maison / maker.

Reset history.

Service history.

Ownership

Invoice.

Seller.

Acquisition date.

Transfer history.

Insurance documentation.

The objective is not to make diamond collecting bureaucratic.

It is to preserve the distinctions that the market keeps trying to collapse.

The strongest buying question is slightly earlier.

What is the material, and what has the laboratory actually established about it?

Then:

How did this diamond form?

Then:

If laboratory-grown, how was it grown?

Then:

Was it treated after formation or growth?

Then:

How is its quality described under this laboratory’s current or historical reporting system?

Only then should the collector look at price.

Natural, laboratory-grown and treated are not three competing labels.

They are answers to different questions.

A serious report keeps them separate.

A serious collector file should do the same.