How to Read Your Diamond Certification Report
When buying a diamond, understanding its quality and characteristics will help you in your purchase. This guide will help you to navigate and interpret your diamond certification report effectively.
Not all diamonds will have a certificate – but if you are keen to purchase a certificated stone – then the grading report will give you all the information you need to know about your stone. The majority of our certificated diamond will come with reports either from the International Gemological Institute or the Gemological Institute of America (GIA). We also work with stones certified by the HRD (Hoge Raad Voor Diamant) in Antwerp and the European Gemological Laboratory. These are all trusted organisations in the jewellery industry that provide detailed insights into the diamond’s attributes. Each certificate will have a serial number and a watermark or hologram.
What is a Diamond Report?
A diamond report is an official evaluation of a diamond’s quality based on several key criteria. There are a number of respected gemological laboratories globally, and their reports are widely recognised for their accuracy and reliability. This document includes details on the diamond’s cut, colour, clarity, carat weight, and other important characteristics that determine its overall value.
Key Components of a Diamond Report
Diamond reports will cover several essential sections. Understanding these will allow you to interpret the report correctly.
The 4 Cs
At the core of every diamond grading report are the "4 Cs"—Cut, Colour, Clarity, and Carat weight. These factors define a diamond’s quality and value:
- Cut: Describes how well the diamond has been shaped and faceted. The cut affects how light interacts with the stone, influencing its brilliance and sparkle. Grading ranges from Excellent to Poor.
- Colour: Diamonds are graded on a scale from D (completely colourless) to Z (light yellow or brown). The most valuable diamonds tend to be colourless or near-colourless.
- Clarity: Evaluates the presence of internal (inclusions) or external (blemishes) imperfections. Clarity grades range from Flawless (no visible inclusions under 10x magnification) to Included (flaws visible without magnification).
- Carat Weight: Indicates the diamond’s weight. One carat equals 200 milligrams. Larger diamonds are rarer and typically more valuable.
Additional Details
Beyond the 4 Cs, the report may include:
- Measurements: The diamond’s dimensions (length × width × depth).
- Proportions: Specific angles and percentages affecting light reflection.
- Fluorescence: Indicates whether the diamond emits a glow under UV light, which may impact its appearance in different lighting conditions.
Diamond Diagram
Most reports feature a diagram illustrating the diamond’s proportions and any inclusions. This visual representation helps assess how imperfections may impact its overall beauty.
How to Interpret Your Report
Understanding your report allows you to evaluate your diamond more effectively. Here’s what to focus on:
Assessing Quality
- Cut Quality: A well-cut diamond maximises brilliance. Prioritise cut over other factors for the best sparkle.
- Colour Grade: Diamonds graded D-H generally appear colourless to the naked eye, making them highly desirable.
- Clarity Rating: Some inclusions are invisible to the unaided eye but affect price. Decide whether you prefer a flawless stone or are open to minor imperfections for cost savings.
- Carat Weight: Larger diamonds are rarer and more expensive. Balance size and quality based on your budget.
Comparing Diamonds
If you’re considering multiple diamonds, compare their reports side by side:
- Prioritise cut grade, as it has the most impact on appearance.
- Compare colours, this helps you to understand the differences.
- Examine clarity, as two diamonds may look similar but have different internal characteristics.
Conclusion
A diamond report may seem complex at first, but understanding its key components will empower you as a buyer. Not all diamonds will have a certificate - and you may not be concerned about purchasing a stone with documentation. But if you are considering purchasing any stone then focusing on important factors like cut quality and colour is important. Grading reports can help you to make a confident, well informed purchase. You can read more about the diamonds that we use – including non-certificated repurposed antique stones here. We also have information on the debate over lab grown and natural stones here.
