HRD Certification: A Deep Dive into Diamond Grading

Last Updated on August 31, 2023 by Juli "Jewels" Church

Embarking on the journey to purchase a diamond — be it an emblem of love, a statement of success, or an heirloom for future generations — is no small feat.

Navigating the labyrinth of choices, from cut to carat, demands not just financial investment but also a mastery of gemological intricacies. However, beyond the dazzle and allure, lies the cornerstone of diamond buying: certification.

HRD Certification

While the Gemological Institute of America (GIA) has long been recognized as the gold standard in this domain, HRD certification is another important player. In this multifaceted guide, we'll dissect the intricate landscape of diamond certification, giving special attention to HRD certification as well as its more globally recognized counterpart, GIA. Armed with this knowledge, you'll be poised to make a diamond investment that is not just financially judicious but also emotionally resonant.

Bottom Line Up Front

Navigating the realm of diamonds can be labyrinthine, filled with intricate twists and turns. While HRD certification offers a robust assurance of a diamond's quality, I must stress that it doesn't supersede the global recognition and stringent standards set by the Gemological Institute of America (GIA).

If you're planning a diamond purchase, my unequivocal recommendation is to insist on a GIA certification. It's a universally acknowledged benchmark that garners immediate trust and lays a solid foundation for your investment, both emotionally and financially. An HRD certification is beneficial, but when it comes to long-lasting value and peace of mind, GIA still reigns supreme.

For further enlightenment, peruse my articles on diamond certifications and the 4Cs explained.

A Brief History of HRD

Embarking upon a temporal expedition, one discovers that HRD Antwerp, originally named "Hoge Raad voor Diamant" — which translates to "Diamond Hight Council" — has a storied history that traces its origins back to 1976. Situated in the heart of Antwerp — often dubbed the "diamond capital of the world" — HRD was conceived to fortify Belgium's critical role in the global diamond industry, with the Antwerp World Diamond Centre (AWDC) as one of its main shareholders


The post-World War II era saw Antwerp aspiring to reestablish itself as a global hub for diamond commerce. It was within this climate that HRD was instituted, offering scientific research, educational initiatives, and, notably, the certification of diamonds. Created with the objective of fostering transparency and ethical trading practices, HRD aimed to be a vital component in both the Belgian and global diamond industries.

Evolutions and Milestones

Over the years, HRD has persistently refined its grading standards, integrating modern technologies such as laser inscription and 3D modeling. The organization further solidified its standing by achieving ISO accreditation in the early 2000s. This development expanded the organization's credibility, although HRD diamond certificates have not gained universal acceptance.

Global Positioning

While HRD purports to be a world authority on diamond grading, it's worth noting that the organization is not universally regarded as such, particularly in the United States. In countries like America, HRD certification is not typically seen as a fully interchangeable substitute for those from the Gemological Institute of America (GIA) or the American Gem Society (AGS).

Adaptations and Innovations

HRD underwent significant rebranding in 2007, transitioning from the High Diamond Council to HRD Antwerp. This rebrand included modernizing their grading reports on polished diamonds to be more consumer-centric, while retaining the scientific rigor they had been known for.

The organization has also moved towards digital platforms, offering online verifications and utilizing advanced imaging technologies. As part of a broader ethical initiative, HRD certificates now affirm adherence to the Kimberley Process to ensure responsible sourcing.

In the grand tapestry of diamond certification, "Hoge Raad voor Diamant" may be a misnomer, but it has its own specific patch, contributing to the wider schema of industry standards and practices.

The HRD Natural Diamond Grading Report

HRD Antwerp provides a Diamond Grading Report as one of its core services. This document aims to offer an in-depth look into various characteristics when grading polished diamonds, serving as a reference tool for both diamond dealers and buyers.

Let's check out the different elements in this report.

HRD Antwerp Diamond Report Sample


Every HRD Diamond Report features a unique identification number and lists the diamond's physical measurements, contributing to its traceability.

4Cs Analysis

Cut and Proportions

In the "Cut and Proportions" section of HRD's report, a diamond's cut is assessed, but the organization takes it a step further by also providing subgrades on proportions, polish, and symmetry.

  • Proportions: This metric assesses the dimensions and angles of a diamond. It scrutinizes how well the facets interact with light, impacting the diamond's overall brilliance and fire.
  • Polish: This refers to the quality of a diamond's surface condition. A superior polish grade means fewer surface imperfections are visible under magnification.
  • Symmetry: This is an evaluation of the exactness of a diamond's shape and the arrangement of its facets. A symmetrical diamond will have uniform and well-aligned facets, contributing to its overall appearance and brilliance.


The carat weight in HRD's report is recorded with high precision, measured to two decimal places. Carat weight plays a substantial role in the diamond's value. This measurement is consistent across all diamond labs.


HRD grades on clarity is different from most other certification bodies. It ranges from LC (Loupe-Clean), meaning no inclusions or blemishes are visible under 10x magnification, to P3 (Piqué 3), indicating noticeable inclusions and/or blemishes that are easily visible to the naked eye and may affect transparency and brilliance.


HRD grades color on a scale from D, representing colorless diamonds, to Z, which indicates diamonds with noticeable color. This is in line with internationally recognized standards. The grading is performed under controlled lighting conditions to ensure uniformity and reliability.

Grading Variability

It's important for buyers to note that HRD's grading scales may not align perfectly with those used by other major institutions. Specifically, HRD-graded diamonds often receive color and/or clarity grades that are approximately two grades higher than what the Gemological Institute of America (GIA) would assign to the same diamond.

Consequently, diamonds with HRD certificates are frequently priced higher than their GIA-certified counterparts. This differential creates an opportunity for diamond dealers to realize higher profit margins, potentially at the buyer's expense. Therefore, it's crucial for prospective diamond purchasers to be aware of this disparity when considering diamonds graded by HRD.

Additional Graphical Data

The report also includes graphical elements such as proportion diagrams and inclusions maps to offer a more comprehensive understanding of the diamond's attributes.

Other HRD Diamond Grading Reports

While the Diamond Grading Report may be HRD Antwerp's flagship offering, the organization provides an array of other reports tailored to various needs and specifications. These alternative reports showcase HRD's multifaceted approach to gemstone evaluation, while also illustrating the breadth of options available to consumers and traders alike.

Jewellery Report

Designed for finished jewelry pieces that incorporate diamonds or other precious gemstones, the Jewellery Report provides a comprehensive analysis of the jewelry item in its entirety. This includes details about the metal used, as well as the grade, size, and arrangement of each gemstone.

Diamond Identification Report

The HRD Diamond Identification Report offers an identification service, focusing specifically on establishing a diamond's provenance and characteristics without going into the grading details. Ideal for those who want to authenticate a diamond's origin, but may not necessarily require a full grading report.

HRD Sample Diamond Identification Report

Diamond ID Card

A more compact alternative to the full grading report, the Diamond ID Card offers essential information on a diamond's 4Cs. However, it's less detailed and may not include some of the more granular data such as fluorescence or plotted diagrams.

Treated Diamond Report

In an age where diamond treatments are increasingly sophisticated, this report is specifically designed to provide information on diamonds that have undergone some form of human intervention—be it laser drilling or high-temperature annealing—to enhance their appearance.

Diamond Colour Grading Report

Ideal for fancy-colored diamonds, the Diamond Colour Grading Report specifically focuses on assessing and grading the unique color attributes of a colored diamond, unlike traditional grading which largely centers around the absence of color.

Gemstone Report

HRD also extends its expertise to other gemstones like rubies, sapphires, and emeralds. These reports describe the gemstone's type, weight, measurements, shape, and color, and identify any treatments the stone may have undergone.

Synthetic Diamond Report

With the rise of lab-grown diamonds, HRD’s Synthetic Diamond Report is increasingly relevant. It provides an exhaustive analysis of synthetic diamonds, making clear distinctions between them and their natural counterparts.

HRD Antwerp Diamond Reports

The "Grading the Graders" Article

The 2013 Rapaport article, aptly titled "Grading the Graders," embarked on a critical mission to scrutinize the methodologies of various grading laboratories, including HRD Antwerp and the Gemological Institute of America (GIA). By doing so, the article catapulted into public discourse questions surrounding the consistency and reliability of grading standards for diamonds.

diamonds certification

Content Overview

The article delved into how each organization approached the evaluation of diamonds, specifically focusing on discrepancies in the grading of the 4Cs—Cut, Carat, Clarity, and Color. It illuminated variances in grading that could lead to significant differences in the valuation of a diamond. For instance, the same diamond could receive different grades depending on which organization evaluated it, raising questions about subjectivity and reliability in grading diamonds.

HRD Antwerp's Spotlight

Of particular relevance to this discussion is the spotlight the article placed on HRD Antwerp. It revealed that HRD's grading often yielded higher color and clarity grades compared to its counterparts, notably the GIA. This finding underscored the potential for price inflation if you're buying an HRD-certified diamond, generating benefits for sellers but potentially leading buyers to pay more than the intrinsic value of the diamond as assessed by universally acknowledged grading metrics.

The article posited that HRD's inconsistent grading could impact its reputation and credibility, especially when compared to more universally accepted grading entities like GIA. While HRD certificates may be highly regarded in certain markets, their value may not hold the same weight globally due to these inconsistencies.

Significance and Impact

The ramifications of this journalistic endeavor were multilayered. On one hand, it served as a wake-up call for both industry insiders and consumers, advocating for a heightened awareness of the nuances in grading practices. On the other, it inadvertently emphasized the credibility of certain longstanding institutions like the GIA, pushing others like HRD to reassess and recalibrate their grading methodologies to align more closely with globally recognized standards.

HRD vs GIA Grading Standards

Certification in the diamond industry is predominantly occupied by a few major players, among which HRD Antwerp and the Gemological Institute of America (GIA) are particularly notable. While both organizations aim to provide a reliable assessment of a diamond's quality based on the universally accepted 4Cs — Cut, Carat, Clarity, and Color — their grading standards exhibit marked differences.

Cut and Proportions

GIA’s focus on the Cut primarily deals with the quality of a diamond’s angles, proportions, and other factors that influence its brilliance and fire. HRD, on the other hand, presents a more detailed sub-categorization within its "Cut and Proportions" section, issuing subgrades on proportions, polish, and symmetry.

Clarity Scale

When it comes to Clarity, GIA uses terms ranging from "Flawless" to "Included," while HRD employs a slightly different nomenclature. Their scale starts from LC (Loupe-Clean), a grade implying that the diamond is free from inclusions and blemishes under 10x magnification, and goes down to P3 (Piqué 3), indicating easily visible imperfections that might affect the diamond's transparency and brilliance.

Consistency and Reliability

The GIA is generally considered the gold standard for grading diamonds, especially in the United States. HRD, although a respected entity, particularly in European markets, has been noted for inconsistencies in its grading.

As pointed out in the 2013 Rapaport article "Grading the Graders," an HRD-certified diamond may to receive higher grades for color and clarity than it might under GIA’s evaluation. This variance can lead to an inflated market value for HRD-certified diamonds, a fact that consumers must consider carefully.

Geographical Recognition

The GIA is widely recognized and accepted globally, whereas HRD Antwerp’s certification holds significant weight in Europe but is not as universally acknowledged. This lack of widespread recognition can impact the resale value of an HRD diamond in certain markets.

Buyer Implications

For potential buyers, these disparities underscore the necessity of a nuanced approach when purchasing diamonds. An HRD certification may be considered reliable, but if one is seeking a universally recognized valuation, a GIA diamond may be the more prudent choice.

FAQs on HRD Antwerp Certification

Is HRD certification reliable?

HRD certification is widely respected, especially in European markets. However, it's important to note that HRD's grading scales can be more generous than those of the GIA, particularly in the realms of color and clarity. Always exercise caution and compare grades from multiple sources when possible.

Is HRD certification accepted globally?

While HRD certification holds significant weight in European markets, it is not as universally acknowledged as GIA certification, particularly in the United States. This could impact the resale value of an HRD-certified diamond in certain regions.

How often does HRD update its grading standards?

The frequency with which HRD updates its grading standards is not publicly documented. However, reputable grading labs, including HRD, periodically review and update their methods in line with advancements in gemological science.

Can HRD certification be done online?

HRD does not currently offer online certification. Physical inspection by HRD's trained gemologists is a crucial component of their certification process.

Do HRD certificates have an expiration date?

HRD certificates themselves don't expire, but the diamond market does evolve. Changes in grading standards or market value can make older certificates less accurate in terms of a diamond's current quality and value.

What is the process for disputing an HRD grade?

If you disagree with the grade assigned by HRD, the first step is typically to contact their customer service to understand the appeals process. A re-examination of the diamond might be possible, often for an additional fee.

How does HRD handle conflict diamonds?

HRD Antwerp is committed to the Kimberley Process, which aims to eliminate the trade in blood diamonds. Any diamonds sent for certification are rigorously checked for compliance with this international agreement.

Can I get a diamond re-certified by HRD if it's already been graded by another lab?

Yes, HRD does offer services for re-certifying diamonds that have been previously graded by other labs. However, the grading may differ due to HRD's unique evaluation standards.

Does HRD offer educational courses for the public?

HRD Antwerp does offer a range of educational services, aimed at both industry professionals and diamond enthusiasts. These often cover various aspects of gemology, grading, and even jewelry design.

What security features do HRD certificates offer?

HRD certificates come with various security features to prevent forgery, such as holograms, security threads, and watermarks.

Is HRD involved in any research and development in gemology?

HRD has a research department dedicated to the advancement of gemological science. They collaborate with institutions and experts globally to stay at the forefront of the field.

The Final Cut

There's a labyrinthine world behind the sparkle and allure of diamonds—a world marked by precision, meticulous evaluation, and varying grading standards. HRD Antwerp offers an alternative to more recognized grading entities like the GIA, especially in European markets. Yet, understanding the nuances, from the types of reports offered to the grading inconsistencies, is key to making an informed decision.

While HRD's methods are widely respected, our key insight remains: If you're looking to make a diamond purchase that holds universally recognized value, GIA-certified diamonds still hold the ace card. HRD offers an extensive range of reporting types and has a strong historical legacy, but the grading disparities, especially when it comes to color and clarity, can't be overlooked.

As you journey through the multifaceted world of diamonds, keep your compass set on knowledge and scrutiny. That's your best guarantee for a purchase that truly reflects what you're looking for: a diamond that shines as brilliantly as your own unique story.

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