rough, polished

Evaluating diamond rough

Evaluating diamond rough

Equipment needed for evaluating diamond rough, a 10× jeweler’s loupe, portable scale, latest rapaport price list, and a calculator.

This is the basic diamond equipment artisanal or small scale miners would need to determine the value of the diamond rough they mine.

The challenge for artisanal miners who make up a significant percentage of the diamond school’s students. is a lack of access to evaluation software used by large-scale manufacturing facilities and organizations, such as De Beers.

Our rough diamond grading and evaluation course help the miner examine samples of rough to compare their finds with to help them determine what can be polished from the raw product and other costs such as laboratory costs.

Natural rough, raw, crude, uncut diamond prices. The difference in the quality of rough diamonds.

The table below shows the 4Cs for Polished Diamonds vs. Evaluation Factors for Rough Diamonds

Polished Rough
Carat Weight Carat Weight
Cut Shape/Make
Clarity Quality
Color Color

With knowledge of the above the student without access to large-scale manufacturing operations – can effectively evaluate rough.


The first step is to sort a parcel of rough by size or carat weight.


Separate the cubes, octahedrons or dodecahedrons and which polished shapes are fetching the highest prices.

Diamond cutters have to pay attention to the internal grain, whether that is the cleavage direction or differential hardness we see in diamonds. These are going to dictate what can be polished from these stones.

When a stone’s internal directions aren’t obvious, that unique surface features can provide clues.


Diamond rough’s quality – the equivalent to polished goods’ clarity – is the next aspect for evaluation. Inclusions and their reflections, as well as areas of stress and strain, must be considered.

Evaluating diamond rough
Diamond Rough Training School


When it comes to color, the rough evaluation doesn’t utilize the D-Z scale, It’s light, medium, and fancy colors.

In general, the “less is more” rule applies – except in the case of fancy colors, which are an entirely different proposition.

The color’s not going to look the same once it’s polished.

What to learn more about diamond rough  At the end of the day, it’s always going to come down to value. What’s my yield going to be? What percentage of this rough yield am I going to be retaining after the diamond cutting and polishing process? It’s always going to come back to a good education

Do you what to learn how to price diamonds and evaluate and process diamond?

Corlia offers a Rough Diamond ONLINE Distance training for part-time study online.

The diamond training is comprised of online tutorials and youtube videos.

Course material will be sent to to you by door to door courier. Free local shipping included.

Learning material includes:

  • Corlia Roberts Rough Diamond Training Manual,
  • Carat weight Diamond Scale
  • Diamond Loupe,
  • Diamond tweezer
  • Scratch pen
  • Diamond light
  • UV light
  • Login-in details to our online portal

You will need to attend a one day practical were you will be able to view parcels of rough diamonds

Personal training instructors are available on WhatsApp and Zoom classroom, to provide support, guidance, and any questions you may have.

This course is identical in contents and outcomes to our contact-based course and successful students will be awarded a certificate.

Cost of the course South Africa R11500.00 / International USD $1200.00

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Our online support hours

South Africa Standard Time – Time zone (GMT+2)

9:00 AM – 2:00 PM
9:00 AM – 9:00 PM
9:00 AM – 9:00 PM
9:00 AM – 9:00 PM
9:00 AM – 9:00 PM
9:00 AM – 7:00 PM
9:00 AM – 5:00 PM

If you looking to get a diamond dealers licence in South Africa, we would recommend doing our rough diamond grading and evaluation course online the cost R11500, You will need to attend a one-day practical in Pretoria or Cape Town presented monthly.

To give you an idea of the format please try the first lesson it will work on your mobile phone as well.

The fee includes assistance with licence application for a diamond dealer’s licence and business plan as per the requirements of the mining charter, which we will complete and submit for you. The licence is valid for 5 years. You can have a home office for this purpose.

Please complete the online enrollment form: and an invoice will be generated.

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