Choosing a diamond is an exciting part of creating a piece of fine jewellery, whether you are designing a bespoke engagement ring, celebrating a milestone or investing in a timeless piece to treasure for years to come. But with so many diamonds available, how can you be confident you are choosing the right one?
This is where diamond certification and grading reports come in.
A diamond grading report provides important information about a diamond’s characteristics, helping you understand its quality and compare different stones before making a purchase. Two of the most recognised names in diamond grading are the International Gemological Institute (IGI) and the Gemological Institute of America (GIA).
At Kmari & Co, we believe choosing a diamond should feel exciting, personal and informed. In this guide, we explain what diamond certification means, what IGI and GIA reports tell you, the difference between the two laboratories, and how to use a grading report when choosing your perfect diamond.
What Is Diamond Certification?
Diamond certification is a document that records a diamond’s characteristics following an assessment by a gemological laboratory.
A grading report helps you understand the diamond you are purchasing by providing details such as its carat weight, colour, clarity, cut and identifying characteristics. Depending on the laboratory and report type, it may also include measurements, diagrams and information confirming whether the diamond is natural or laboratory-grown.
It is important to understand that a grading report is not the same as a valuation. A grading report describes a diamond’s characteristics, whereas a valuation estimates its monetary worth for a particular purpose, such as insurance.
A report also does not automatically guarantee that a diamond is the right choice for you. It is a valuable tool that helps you make an informed decision alongside your budget, personal preferences and the design of your jewellery.
One of the most important sections of a diamond grading report is the 4Cs: cut, colour, clarity and carat weight. Understanding these characteristics can help you compare diamonds and decide which qualities matter most to you.
What Is an IGI Diamond Report?
The International Gemological Institute (IGI) is a well-established gemological laboratory that issues grading reports for natural and laboratory-grown diamonds.
An IGI diamond report provides information about the stone's characteristics, helping buyers understand what they are purchasing and compare diamonds using documented grading criteria.
IGI is widely used for both natural and lab-grown diamonds. Its reports can be particularly useful when comparing laboratory-grown diamond options and understanding their documented characteristics.
What Is a GIA Diamond Report?
The Gemological Institute of America (GIA) is an independent gemological organisation known for its work in diamond research, education and grading.
GIA grading reports for natural diamonds provide a detailed assessment of the stone's characteristics, including the 4Cs. Depending on the report, additional information may include measurements, a plotted clarity diagram, proportions and identifying details.
GIA also provides services for laboratory-grown diamonds. Its current laboratory-grown diamond assessment system differs from its traditional grading system for natural diamonds, so it is important to check which type of report accompanies the stone.
You can use GIA's official report verification service to check the details of a GIA report.
Is a GIA diamond better than an IGI diamond?
Not necessarily. The laboratory named on a report does not, by itself, determine which diamond is the better choice.
Two diamonds with similar stated grades may still differ in their proportions, light performance, inclusions and overall appearance. It is important to consider the individual diamond, the details recorded in its report and how it looks in person.
The grading system used can also vary, particularly between natural and laboratory-grown diamonds. This means you should not automatically assume that identical-looking grade labels across different report types represent precisely the same assessment.
Rather than choosing a diamond based on the laboratory name alone, look at the complete report and seek guidance from a jeweller who can help you understand the differences.
At Kmari & Co, we believe fine jewellery should be as individual as the person wearing it. As a fourth-generation jeweller based in Hampshire, we bring a personal approach to creating bespoke pieces designed to be treasured.
Whether you are looking for a natural diamond, a lab-grown diamond, a bespoke engagement ring or a meaningful piece of fine jewellery, we can help you explore your options.
Our bespoke process is centred around you. We take the time to understand your preferences, desired design and budget, helping you navigate diamond characteristics and grading reports without unnecessary jargon.
From selecting your diamond to developing your design, we want you to feel informed and confident at every stage of your journey.
We deliver across the UK and can even come to you for a personal consultation, making it easier to explore your options and begin designing a piece that is uniquely yours.
Choosing a diamond should be an exciting experience, not a confusing one. Understanding IGI and GIA reports can help you compare diamonds, explore your options and feel more confident about your decision.
We're jewellers based in Hampshire, and we'd love to guide you through your options, whether you're after a natural or lab-grown diamond. We deliver across the UK, and we can even come to you for a personal consultation.
Message us to start your bespoke journey: hello@kmari.co.uk
