IGI, GIA & independent laboratory reports

Lab Grown Diamond with an independent gemological laboratory report
ROSY DIAMOND KNOWLEDGE

IGI, GIA & independent laboratory reports

Independent gemological laboratories examine and document Diamonds according to defined procedures.

IGI and GIA are internationally recognized institutes; however, their current reporting systems for Lab Grown Diamonds are not identical.

FUNDAMENTALS

Why independent laboratories matter

When purchasing a Diamond, the product description and sale come from the dealer. An independent gemological laboratory report serves a different purpose: It documents the examination of the specific Diamond by an external specialist institute.

1

Identification

Among other things, the laboratory determines whether a Diamond is of natural or laboratory origin.

2

Assessment

Gemological properties are examined according to the institute’s respective system.

3

Documentation

The examination results are recorded in a clearly attributable report.

Independent does not mean “all laboratories work identically.”Institutes may use different report types, terminology, and grading systems.
Independent gemological laboratory during the examination of a Diamond
THE LABORATORY WORK

What happens during the gemological examination?

A professional laboratory uses trained gemologists, controlled examination conditions, and specialized instruments.

For Lab Grown Diamonds, this particularly includes determining their origin. Depending on the service and report, quality and identification characteristics are also examined.

  • determination of natural or laboratory origin
  • weight and measurements
  • color and clarity or the corresponding quality assessment
  • cut and finish characteristics, where provided
  • gemological identification characteristics
  • where applicable, growth and treatment information
IGI

What is the International Gemological Institute?

IGI stands for International Gemological Institute. The institute examines natural and lab-grown Diamonds, as well as other gemstones and Jewelry.

For Lab Grown Diamonds, IGI continues to use the familiar 4C system. Such a report may document, among other things, Carat, Color, Clarity, Cut – where applicable –, measurements, polish, symmetry, and laboratory origin.

Especially relevant for ROSY ROSY uses independent IGI grading reports for individual Lab Grown Diamonds that meet the relevant criteria.
GIA

What is the Gemological Institute of America?

GIA stands for Gemological Institute of America and is also an internationally established gemological institute.

For suitable colorless to near-colorless lab-grown diamonds, GIA changed its reporting system in October 2025. Instead of fully adopting the terminology known for natural diamonds, GIA uses its own general quality assessment.

Premium

Refers to lab-grown diamonds that meet the higher criteria defined by GIA in its current quality assessment.

Standard

Refers to lab-grown diamonds that meet the minimum requirements defined by GIA for this grading level.

That is why you should not convert them directlyA GIA term such as “Premium” is not a substitute letter for a specific IGI Color or Clarity Grade. These are different reporting systems.
Different formats of independent diamond laboratory reports
REPORT FORMATS

Why do laboratory reports look different?

A laboratory report is not a globally identical standard form.

Institutes may use different layouts, terminology, grading models, and additional information.

Even within a single institute, there can be different report types for different kinds of diamonds or services.

The laboratory’s name is only the beginning.For a meaningful comparison, you need to know which specific report type and grading system you are looking at.
IGI & GIA

Can the reports be compared directly?

Not always. Especially with today’s lab-grown diamonds, different grading systems should not be treated as though their information were automatically interchangeable on a one-to-one basis.

IGI

Continues to use 4C-based documentation for lab-grown diamonds and identifies their laboratory origin.

GIA

Uses the categories Premium and Standard for its current quality assessment of suitable colorless to near-colorless lab-grown diamonds.

No rankingIt is not possible to reliably conclude from different reporting systems that one institute is categorically “better” or “worse.” What matters is which examination was performed and what the specific report documents.
DISCREPANCIES

Can laboratories assess a diamond differently?

Gemological assessments are carried out according to the rules and procedures of the respective institute. In borderline cases, differences may therefore occur between assessments from different laboratories or systems.

For this reason too, information from different reporting systems should not be equated without context.

Remain consistent when comparingIf you want to compare two diamonds as directly as possible, reports from the same institute and of the same report type are particularly helpful.
ONLINE VERIFICATION

Why should I verify a report online?

A reputable laboratory report has a unique identification or report number.

IGI and GIA offer their own online services for verifying report data and archived report information.

  • enter report number
  • access stored laboratory data
  • Compare the document and the data
  • Do not ignore discrepancies
Always use the official laboratory website.A photo or PDF of a report alone is less informative than additionally comparing it with the data stored by the issuing laboratory.
Online verification of a diamond laboratory report
Laser inscription on the girdle for matching a diamond to its report
LASER INSCRIPTION

The connection between a diamond and its report

A microscopic laser inscription on the girdle can make it easier to match a diamond to its documentation.

Depending on the laboratory and service, a report or assessment number and other identifying information may be engraved.

Combine multiple levels of verificationLaser inscription, report number, online verification, and gemological characteristics should be considered together. A visible number alone is not an absolute guarantee of authenticity.
GROWTH & TREATMENT

What additional information may be important?

For lab-grown diamonds, information about the growth process or detected post-growth treatments may be relevant.

Growth Method

May indicate CVD or HPHT growth, for example.

Post-Growth Treatment

Describes a possible technical treatment after the actual crystal growth.

Which information is displayed depends on the institute, report type, and the examination in question.

ROSY STANDARD

Which laboratory reports does ROSY use?

For a single Lab Grown Diamond weighing 0.50 ct or more, ROSY Lab Diamonds provides an independent IGI Grading Report as well as the ROSY Product Certificate.

The threshold applies per stone.Several smaller diamonds whose combined weights total 0.50 ct or more do not automatically meet this requirement.

The ROSY product certificate documents the jewelry piece and should not be equated with the independent gemological IGI Grading Report.

PURCHASE ADVICE

What should I look for in a laboratory report?

  • First check which institute issued the report.
  • Pay attention to the specific report type.
  • Do not read just a single quality grade.
  • Do not blindly compare the systems of different institutes on a one-to-one basis.
  • Check the laboratory's origin and identification details.
  • Check for any information about growth and post-treatment.
  • Verify the report through the institute's official service.
  • Compare any existing laser inscription with the documentation.
  • Also assess the actual diamond and the jewelry piece.
IN BRIEF

IGI, GIA & Laboratory Reports at a Glance

  • Independent laboratories examine diamonds separately from the sales process.
  • IGI and GIA are well-known gemological institutes.
  • Their current reporting systems for Lab Grown Diamonds are not identical.
  • IGI continues to use its 4Cs-based grading for Lab Grown Diamonds.
  • GIA uses Premium and Standard for its corresponding current Lab Grown Diamond grading.
  • Different systems should not be converted directly on a one-to-one basis.
  • Report numbers can be verified through official laboratory services.
  • A laser inscription helps match the stone to its documentation.
  • A laboratory report remains a source of information—not a guarantee of future market value.
ROSY DIAMOND KNOWLEDGE

Understanding Laboratory Reports. Comparing Information Correctly.

It is not simply the most famous name that decides. What matters is who examined the diamond, which system was used, and what information the specific report provides.

Discover Diamond Knowledge Understanding Diamond Certificates ROSY Lab Grown Diamond Certificate