Understanding diamond certificates

Diamond Certificates and Gemmological Quality Reports
ROSY DIAMOND KNOWLEDGE

Understanding Diamond Certificates

An independent Grading Report documents the gemmological characteristics of an examined Diamond.

Anyone who understands the key information can better assess origin, quality, and identification.

FUNDAMENTALS

Certificate or Grading Report?

In everyday usage, people often refer to a Diamond Certificate. However, for the independent gemmological examination of a loose Diamond, Grading Report is the more precise term.

Such a report documents the results of a professional examination of the specific Diamond.

Important A Grading Report is neither a proof of purchase nor a guarantee of a specific future market value. It documents gemmological characteristics at the time of examination.
Lab Grown Diamond with an independent gemmological Grading Report
INDEPENDENT EXAMINATION

Who Issues a Grading Report?

Independent gemmological institutes examine Diamonds using specialized methods and instruments.

For a Lab Grown Diamond, this concerns not only the classic quality characteristics but also the identification of its laboratory origin.

IGI Example ROSY Lab Diamonds uses independent IGI Grading Reports for individual Lab Grown Diamonds that meet the relevant qualifications.
THE MOST IMPORTANT INFORMATION

What Can a Diamond Report Contain?

1

Identification

For example, laboratory origin, report number, shape, and cut style.

2

4C

Carat, Color, Clarity, and—insofar as applicable to the Diamond—Cut.

3

Additional Data

Measurements, polish, symmetry, proportions, and other gemmological characteristics.

The exact scope may vary. Not every report type or Diamond shape contains exactly the same fields or assessments.
READ THE REPORT

Understanding the Information Step by Step

Reading and Understanding a Diamond Grading Report

Carat Weight

Documents the exact weight of the examined Diamond.

Measurements

Show the length, width or diameter, and depth in millimeters.

Color

Describes the gemmologically determined color grade or, in the case of Fancy Colors, the color appearance.

Clarity

Describes the clarity grade based on the clarity characteristics examined.

Cut

For applicable Diamonds, can document the cut quality.

Polish & Symmetry

Describe important aspects of surface finishing and geometric execution.

LAB GROWN ORIGIN

How is the laboratory origin documented?

For a Lab Grown Diamond, it must be clearly evident that it is a Lab Grown Diamond and not a natural Diamond.

The report may also include information about the identified growth process.

CVD

Chemical Vapor Deposition refers to a controlled growth process in an activated gas environment.

HPHT

High Pressure High Temperature refers to growth under very high pressure and high temperature.

Growth method ≠ quality grade CVD or HPHT describes how the diamond was formed. The quality of the finished diamond must be assessed separately.
POST-GROWTH TREATMENT

What does a reference to post-growth treatment mean?

For certain laboratory-grown diamonds, technical procedures may be used after the actual growth to change, for example, their color properties.

If such post-growth treatment is detected during examination and documented in the relevant report type, it may appear in the report's comments or details.

Do not confuse it with the growth method For example, a CVD diamond may undergo HPHT post-growth treatment. Its growth method nevertheless remains CVD.
LASER INSCRIPTION

How can the diamond be matched to the report?

Many documented diamonds may have a microscopic laser inscription applied to the girdle.

For example, it may contain a report number, making it easier to match the stone to its documentation data.

  • is typically located on the girdle
  • is usually barely visible without magnification
  • can support identification
  • can be cross-checked with report data
An inscription alone is not sufficient as an absolute guarantee of authenticity. The report should also be checked using the official verification function of the issuing laboratory.
Laser inscription on a diamond's girdle for report identification
REPORT NUMBER

Why online verification is useful

Independent laboratories provide ways to verify report data using a unique report number.

This makes it possible to check whether the documentation data at hand matches the information stored by the laboratory.

Transparency through multiple layers The report number, online verification, laser inscription, and professional examination of the diamond complement one another for identification.
WHAT A REPORT DOES NOT SAY

A Grading Report does not answer every purchasing decision

A report provides important objective information. However, it does not replace every visual or personal assessment.

No price promise

The report does not guarantee any future sale or resale value.

No style consultation

It does not determine which shape, size, or color grade you personally prefer.

Not a complete jewelry appraisal

A report for a loose diamond does not automatically describe all the characteristics of the finished piece of jewelry.

Difference between a Diamond Grading Report and a Jewelry Product Certificate
TWO DOCUMENTS

IGI Diamond Grading Report and ROSY Product Certificate

These two documents serve different purposes and should not be confused.

Independent IGI Grading Report

Documents the gemological examination and quality characteristics of the specific individual diamond by an independent laboratory.


ROSY Product Certificate

Documents your jewelry piece and the associated product information from ROSY Lab Diamonds. It is not an independent gemological laboratory report.

ROSY CERTIFICATION STANDARD

Which documents do you receive from ROSY?

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

The weight of the individual diamond is decisive. The 0.50 ct threshold does not refer to the combined total carat weight of several smaller diamonds.

Example A

A single Lab Grown Diamond weighing 0.70 ct meets the ROSY threshold for an independent IGI Grading Report.

Example B

Ten smaller diamonds totaling 0.70 ct do not automatically meet the threshold if no individual stone weighs at least 0.50 ct.

BUYING GUIDE

How to properly evaluate a diamond report

  • Check whether laboratory origin or natural origin is clearly stated.
  • Compare the report number with any laser inscription.
  • Verify the report through the laboratory’s official database.
  • Read Carat, measurements, Color, and Clarity together.
  • Check any Cut, Polish, and Symmetry grades provided.
  • Look for comments on growth methods or post-treatments.
  • Compare the report details with the diamond’s visible appearance.
  • Do not confuse an independent grading report with a retailer or product certificate.
IN SUMMARY

Diamond Certificates at a Glance

  • “Grading report” is the more precise term for an independent gemological report.
  • The report documents the characteristics of the diamond examined.
  • The most important details include the 4Cs, measurements, and identification data.
  • For lab grown diamonds, the laboratory origin is documented.
  • Growth method and post-treatment are different types of information.
  • A laser inscription can help confirm the report’s association with the diamond.
  • The report number should also be verified with the issuing laboratory.
  • A report is not a guarantee of future market value.
  • The ROSY Product Certificate is not an independent gemological grading report.
ROSY DIAMOND KNOWLEDGE

Understand documents. Assess quality more transparently.

A grading report becomes particularly valuable when you know what information it contains and how the details relate to one another.

Discover Diamond Knowledge Understanding the 4Cs ROSY Diamond Certificate