Why you should know about the 4Cs of a diamond

At first glance, two diamonds might look very similar, but have very different values. So, which one is worth more? And, how can you tell?

The answer lies in the 4Cs – carat, colour, clarity and cut. Together, the 4Cs form a universal method of describing diamond quality that is understood by everyone in the industry. It’s a transparent way of determining the value of a stone, especially when differences aren’t clear with the naked eye, so you know what you’re buying.

Let’s take a look at the 4Cs to find out more.

 

Diamond carat

Diamond carat refers to a diamond’s weight, not its size, and is often measured in points. 100 points equals 1 carat, which is 0.2 grams. Be careful you don’t get confused by Diamond Carat Weight and Total Carat Weight (CTW). Diamond Carat Weight refers to the weight of a single diamond, while CTW is the sum of the individual carat weights of all the diamonds in a piece of jewellery.

 

Diamond colour

Diamond colour might be called ‘colour’, but it actually refers to the diamond’s lack of colour. The highest grade – D – is considered to be ‘Exc. White +’ (“Exceptionally White +”). The scale goes down, in 23 steps, from D to Z as the diamonds become progressively more yellowish, brownish or greyish.

Most diamonds used in jewellery are ‘rare white’ to ‘slightly tinted white’, rated between G and J on the scale. Beyond grade K, a human eye can detect a yellow tint. Fancy coloured diamonds are valuable due to their rarity. Red, orange and green diamonds are the most expensive, followed by pink, blue and yellow diamonds.

 

Diamond clarity

This covers the microscopic flaws that (almost) all natural diamonds have. Even though these flaws, known as internal and external characteristics, are usually only visible under 10x magnification, diamond cutters try to cut and polish a diamond to hide these flaws or work around them.

The scale for diamond clarity is:

  • LC – Loupe clean
  • VVS1 and VVS2 – Very, very small inclusions
  • VS1 and VS2 – Very small inclusions
  • SI1 and SI2 – Small inclusions
  • P1, P2 and P3 – Piqué

 

Diamond cut

The cut is the largest influence on a diamond’s sparkle. The diamond’s cut is based on three grades – proportions, symmetry and polish – which all have an impact on how your diamond dazzles. Each grade is evaluated separately and given one of four results:

  • Excellent
  • Very good
  • Good
  • Fair

Diamonds can be cut in many ways, for example to maximise carat weight or minimise internal characteristics (see clarity). However, if it is not cut properly, it will lack sparkle and have a lower result (and value).

Popular diamond cuts include: brilliant, princess, marquise, oval, heart, pear, emerald and cushion.

 

Diamond certification

The 5th (and unofficial) C, is certification. Diamond certification from a trusted and unbiased expert, like HRD Antwerp, is an easy way to discover exactly what you are buying for peace of mind. And, as it gives an independent summary of your diamond’s quality, the certificate can also be used for your insurance.

If in doubt …

If you have any questions about your diamond’s characteristics, ask an expert like HRD Antwerp.

Natural Diamond Grading Report

An HRD Antwerp Natural Diamond Grading Report is an objective report that confirms a polished natural diamond’s authenticity and provides a detailed description of its key characteristics, the so- called 4Cs: Carat, Colour, Clarity and Cut.

Price List

Lab Standard Price

Antwerp Lab
India Lab
Dubai Lab

EXAMINATION

When registered in our lab, your diamond or jewellery will be thoroughly examined by our graders and will undergo the following steps:

WEIGHT

SCREENING

MEASUREMENT

FLUORESCENCE

COLOUR

CLARITY

CUT

The weight of a diamond is expressed in carats. One carat equals 0.2 grams or 100 points, which indicates the size. HRD Antwerp has extremely accurate scales that measure up to five figures after the decimal point.

The first step is to determine if your diamond is natural, laboratory-grown or treated. If a diamond does not pass the initial test, it will be directed to our research department to further determine its nature.

Your diamond is accurately measured in millimetres as mentioned below: minimum diameter – maximum diameter in mm x height in mm (example: 6.44 – 6.47 mm x 4.04 mm)

The fluorescence grade under long wave is mentioned in the report. For the “Natural Diamond Colour Grading Report” the fluorescence grade under short wave is also mentioned.

Most diamonds range in colour from colourless (‘D’) to tinted colour (‘Z’). The colour grade is determined by comparison with a series of master stones, the best grade being D.

All natural diamonds have traces of their growth history, which determines the diamond’s purity. In most gem-quality diamonds, these are minor internal characteristics or inclusions. The very best and rarest stones are graded ‘loupe clean’ or 'LC'.

A diamond’s cut is essential to its beauty and is a combination of craftsmanship and scientific knowledge. The right proportions, symmetry and polish create internal reflections that maximise a stone’s sparkle, brilliance and fire.

ADDITIONAL SERVICES

Take advantage of our additional services to add value to your diamond. For more information and prices, please consult our price lists or contact our helpdesk via e-mail: diamondlab@hrdantwerp.com or +32 3 222 06 25

HEARTS & ARROWS DIAMONDS

LASER INSCRIPTION

SEALING

Hearts & Arrows diamonds are precisely cut round brilliants that, when examined using a special viewer, display eight hearts through the pavilion of the diamond (from below) and eight arrows through the crown of the diamond (from above). The appearance of the pattern is a strong indicator of a top-quality cut.

o inscribe diamonds with lasers, HRD Antwerp uses high-quality excimer shortwave technology. It cannot be seen with the naked eye and consequently does not affect the diamond’s physical appearance or value. Laser inscription can either be used to match your diamond and its corresponding grading report or to customise your diamond with a personalised message or logo.

Sealing guarantees that an issued grading report and the corresponding diamond belong together, and it keeps the diamond safe from oil and dirt. The HRD Antwerp sealing is tamper-proof.

Laboratory Grown Diamond Grading Report

Every diamond is tested to determine whether it is natural. If it is found to be laboratory grown, under disclosed conditions, we will issue a Laboratory Grown Diamond Grading Report, with this clear wording on the cover. Each laboratory grown diamond is laser inscribed with “LAB GROWN” and report number. The presence of the laser inscription is mentioned on the Grading Report, including a reference number and statement that the diamond has been laboratory grown. The same nomenclature as in a Natural Diamond Grading Report is used, with a detailed description of the 4Cs.

Price List

Lab Standard Price

Antwerp Lab
India Lab
Dubai Lab

EXAMINATION

When registered in our lab, your diamond or jewellery will be thoroughly examined by our graders and will undergo the following steps:

WEIGHT

SCREENING

The weight of a diamond is expressed in carats. One carat equals 0.2 grams or 100 points, which indicates the size. HRD Antwerp has extremely accurate scales that measure up to five figures after the decimal point.

The first step is to determine if your diamond is natural, laboratory-grown or treated. If a diamond does not pass the initial test, it will be directed to our research department to further determine its nature.

ADDITIONAL SERVICES

Take advantage of our additional services to add value to your diamond. For more information and prices, please consult our price lists or contact our helpdesk via e-mail: diamondlab@hrdantwerp.com or +32 3 222 06 25

Jewellery Report

Our laboratory has the knowledge and instruments needed to thoroughly analyse your jewellery. An HRD Antwerp Jewellery Report is an official document in which a jewellery item is authenticated for different purposes, such as insurance, inheritance or purchase. It can also be used to determine the market value of a jewel. These reports provide a general description of the jewel, the diamonds it contains and the precious metals of which it is made.

Price List

Lab Standard Price

Antwerp Lab
India Lab
Dubai Lab

EXAMINATION

When registered in our lab, your diamond or jewellery will be thoroughly examined by our graders and will undergo the following steps:

WEIGHT

SCREENING

The weight of a diamond is expressed in carats. One carat equals 0.2 grams or 100 points, which indicates the size. HRD Antwerp has extremely accurate scales that measure up to five figures after the decimal point.

The first step is to determine if your diamond is natural, laboratory-grown or treated. If a diamond does not pass the initial test, it will be directed to our research department to further determine its nature.

ADDITIONAL SERVICES

Take advantage of our additional services to add value to your diamond. For more information and prices, please consult our price lists or contact our helpdesk via e-mail: diamondlab@hrdantwerp.com or +32 3 222 06 25

Natural Diamond Colour Grading Report

This grading report mentions the colour origin of your diamond and describes its colour characteristics, as well as its short- and long-wave luminescence.

Price List

Lab Standard Price

Antwerp Lab

EXAMINATION

When registered in our lab, your diamond or jewellery will be thoroughly examined by our graders and will undergo the following steps:

WEIGHT

The weight of a diamond is expressed in carats. One carat equals 0.2 grams or 100 points, which indicates the size. HRD Antwerp has extremely accurate scales that measure up to five figures after the decimal point.

ADDITIONAL SERVICES

Take advantage of our additional services to add value to your diamond. For more information and prices, please consult our price lists or contact our helpdesk via e-mail: diamondlab@hrdantwerp.com or +32 3 222 06 25

Natural Diamond Identification Report

A special, pared-down grading report exclusively for diamonds under 1.00 ct.

Price List

Lab Standard Price

Antwerp Lab
India Lab
Dubai Lab

Laboratory Grown Diamond Jewellery Report

Our laboratory has the knowledge and instruments needed to thoroughly analyse your jewellery.Every diamond of the jewellery piece is tested to determine whether it is natural or laboratory grown. If all diamonds set in the jewellery piece are found to be Laboratory Grown, under disclosed conditions, we will issue a Laboratory Grown Diamond Jewellery Report, with this clear wording on the cover. This report provides a general description of the jewellery, the laboratory grown diamonds it contains and the precious metals of which it is made.

Price List

Lab Standard Price

Antwerp Lab
India Lab
Dubai Lab

Jewellery Report (Compact)

A compact version of the jewellery report is available exclusively for jewellery containing less than 1.00 ct of diamonds (total weight)

Price List

Lab Standard Price

Antwerp Lab
India Lab
Dubai Lab

Client Registration

Submitting your diamonds or jewels

Our online KYC client registration makes it easy for you to register as a client and submit your diamonds and jewels.

CLIENT KYC

DELEGATION FORM OR AUTHORIZED PERSONNEL FORM

PROFORMA INVOICE TEMPLATE

DIAMOND LIST FORM

JEWELLERY LIST FORM

MY HRD ANTWERP REGISTRATION FORM

CONSIGNMENT MEMO JEWELLERY

DELEGATION FORM OR AUTHORIZED PERSONNEL FORM

DIAMOND LIST FORM

JEWELLERY LIST FORM

MY HRD ANTWERP REGIUSTRATION FORM

CLIENT KYC

MY HRD ANTWERP REGISTRATION FORM

JEWELLERY LIST FORM

DELEGATION FORM OR AUTHORIZED PERSONNEL FORM

DIAMOND LIST FORM

CLIENT KYC

HRD CO-BRANDING PROGRAMME

If you are a diamond seller or retailer who wishes to personalize your grading reportS, The HRD Tailored Grading Programme offers endless possibilities when it comes to co-branding. We liste the most popular options below, and we are always happy to discuss any new ideas you might have.

  • 1

    A PERSONALIZED LOGO

    All of our diamond grading reports can be personalised with a logo of your choice.

  • 1

    A SPECIFIC DIAMOND DRAWING

    A custom diamond drawing can be implemented on the grading report in accordance with your specific shape

  • 1

    A SPECIFIC SHAPE NAME

    A specific shape name can be shown on the grading report, which refers to shapes that are registered or patented.

For more information about necessary registration documents and licenses, please contact the lab location where you have registered.

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