Technology & Grading Process, methods

Advanced Technology

DCLA prides itself on maintaining a truly state-of-the-art diamond laboratory. Technology is a crucial part of DCLA’s diamond grading and certification capabilities.

DCLA is a full-service diamond grading and testing laboratory, with the most innovative and up-to-date equipment available to accurately identify and assess each diamond.

Each and every diamond is screened for all known treatments, tested to ensure that it is a natural and not man-made diamond, and graded in accordance with International Diamond Council (IDC) rules.

Independence & Quality Control

To ensure a fully objective, independent assessment of your diamond, our diamond graders are protected from potential outside influences. How?

Immediately after a diamond is received, it is placed into a DCLA parcel paper (a “briefca”) and assigned a unique identification number – all reference to the submitting customer is removed. This way, grades cannot be inadvertently influenced by associating a diamond with a particular customer.

In addition, multiple diamond graders work independently on every diamond – no grader can be influenced by the grades of another. Thus, they cannot be influenced by anyone else’s opinion. A minimum of three professionals must independently agree for a diamond’s grades to be finalised by the control grader and forwarded to certificate printing.

In this way, we maintain the integrity of our diamond grading process and are confident in offering our Diamond Grading Guarantee.

DCLA Diamond Grading Process 

DCLA has a fully standardised grading process, ensuring that each and every diamond that comes through the laboratory is thoroughly tested for authenticity and graded consistently and accurately according to International Diamond Council (IDC) rules.

Every diamond is:

  • Weighed on a high-precision certified weight scale for exact, accurate weight
  • Measured with specialised computer technology that calculates precise dimensions and proportions
  • Screened for all known treatments and tested to ensure that it is natural and not man-made
  • Colour and fluorescence graded against a set of registered master diamonds, under carefully controlled lighting conditions
  • Clarity-graded under appropriate magnification
  • Plotted for identification purposes under binocular microscopic magnification – a drawing of inclusions is present on every Diamond Certificate
  • Cut-graded for proportions, polish, and symmetry
  • Transparency graded to assess crystal quality

Diamond Technology and Grading Processes and Methods

Diamond technology refers to the techniques used to mine, cut, polish, and treat diamonds to create the final product. Meanwhile, diamond grading refers to the evaluation of a diamond’s quality and characteristics, including its colour, clarity, cut, and carat weight.

Diamond technology and grading are complex and Specialised fields, and there are various methods and processes involved. Here are some of the key techniques and grading methods used in the diamond industry:

Diamond Technology:

Mining: Diamonds are typically mined from deep underground using heavy machinery and explosives.
Cutting and polishing: Once extracted, rough diamonds are cut and polished into the final product using a variety of Specialised tools and techniques.
Treatment: Some diamonds are treated to enhance their colour, clarity, or other characteristics. Treatments may include heating, irradiation, or coating.
Certification: Diamonds are often certified by independent organizations, such as the Gemological Institute of America (GIA), which verifies the diamond’s authenticity and characteristics.

Diamond Grading:

4 Cs: Diamond quality is evaluated based on the “4 Cs”: colour, clarity, cut, and carat weight. These characteristics are assessed using standardized grading scales.

Colour grading: Diamonds are graded on a scale from D (colourless) to Z (yellow or brown), with higher grades indicating a more desirable colour.

Clarity grading: Diamond clarity is evaluated based on the presence or absence of blemishes or inclusions, with higher grades indicating a clearer diamond.

Cut grading: Diamond cut refers to the quality of the diamond’s proportions, symmetry, and polish. A well-cut diamond will reflect light more effectively and appear more brilliant.

Carat weight: Diamond weight is measured in carats, with one carat equaling 0.2 grams.
Overall, diamond technology and grading require Specialised expertise and training, and the industry is highly regulated to ensure consistent quality and standards.


Gemological laboratories use a range of Specialised equipment to assess the quality and characteristics of diamonds. Here are some of the most commonly used gemological instruments in a diamond grading laboratory:

Microscopes: Gemologists use high-powered microscopes to examine diamonds in detail, looking for inclusions, blemishes, and other characteristics that may affect the diamond’s quality.

Loupes: A jeweller’s loupe is a small, handheld magnifier that allows gemologists to see a diamond’s features in greater detail.

Refractometers: Refractometers are used to measure a diamond’s refractive index, which helps to determine its authenticity and identify any treatments that may have been applied to the stone.

Spectrophotometers: These instruments are used to measure a diamond’s absorption and emission spectra, which can provide information about its colour and potential treatments.

Diamond scales: Accurately weighing a diamond is essential for determining its carat weight, so gemologists use Specialised diamond scales that are calibrated to extremely high levels of accuracy.

Diamond colourimeters: These instruments are used to measure the colour of a diamond, helping gemologists to accurately grade its colour based on standardized grading scales.

UV lamps: UV lamps are used to examine diamonds under ultraviolet light, which can reveal certain characteristics that may not be visible under normal lighting conditions.

Polariscope: This instrument is used to analyze a diamond’s optical properties, such as its birefringence and polarization, to determine its authenticity and potential treatments.


Overall, gemological laboratories use a range of Specialised equipment to assess the quality and characteristics of diamonds accurately. These tools are designed to provide accurate and precise measurements, allowing gemologists to make informed decisions about the quality and value of diamonds.
DTC DiamondView and DiamondSure are two diamond grading and analysis instruments developed by the De Beers Group, one of the world’s leading diamond producers and sellers.


DTC DiamondView:
DiamondView is a non-destructive diamond grading instrument that uses advanced technology to create high-resolution images of a diamond’s internal structure. It works by projecting ultraviolet light onto the diamond and measuring the way the light is absorbed and emitted. The resulting images can be used to identify inclusions, blemishes, and other characteristics that may affect a diamond’s quality and value. DiamondView is used by diamond dealers, gemologists, and other industry professionals to assess the quality of diamonds quickly and accurately.


DiamondSure is a handheld instrument that is used to quickly and accurately identify diamonds and distinguish them from other gemstones or simulants. It works by analyzing the way that light passes through a gemstone, using a combination of ultraviolet and visible light. DiamondSure can identify most natural diamonds, as well as many synthetic diamonds, and it can also be used to detect treatments or enhancements that may have been applied to a diamond.

Overall, both DTC DiamondView and DiamondSure are valuable tools for diamond grading and analysis, providing gemologists and industry professionals with accurate and reliable information about the quality and authenticity of diamonds.


The CIBJO Diamond Master Set is a standardized set of diamonds that is used as a reference for colour grading in the diamond industry. The set was developed by the World Jewellery Confederation (CIBJO) and is widely used by diamond laboratories, jewelers, and gemologists around the world.

The Diamond Master Set contains a series of natural diamonds, carefully selected that precisely represent a range of colour grades from D (colourless) to Z (yellow or brown). Each diamond in the set is a round brilliant cut and is carefully calibrated to ensure consistent size and proportions.

The set is used as a reference tool for colour grading, allowing gemologists and other industry professionals to compare a diamond’s colour to a known standard. By examining a diamond in relation to the stones in the Diamond Master Set, gemologists can determine its colour grade more accurately and consistently.

The use of a standardized set like the CIBJO Diamond Master Set helps to ensure that colour grading is consistent across different laboratories and markets, promoting transparency and accuracy in the diamond industry.