Polishing a Diamond: Cost


To determine the price and the process for cutting and polishing a diamond.

Early Findings

There are five stages to diamond cutting and polishing.

Planning the cut of the rough diamond

  • This step usually involves figuring out "the best possible shapes of the diamond in order to minimize waste and maximize the yield of the rough stone."
  • Usually, the process involves the use of specialized programs like a Sarine machine.

Cleaving/sawing a rough diamond

Mechanical Bruting

  • The next step involves making the separate rough diamonds round. The process is called girdling.
  • In order to that, two rough diamond pieces are put across of each other and turned in opposite directions.


  • The polishing process mainly involves creating the diamond's facets, which includes the use of a tang and a scaife.
  • The process is further divided into blocking and brillianteering.
  • In the blocking steps, "8 pavilion mains, 8 crowns, 1 culet, and 1 table facet are added to make a single cut stone" which serve as a template for the brillianteering step.
  • The brillianteering step adds "the remaining facets, bringing it to a total of 57 facets." This is probably the most important step in the whole process as it determines the diamond' fire and brilliance.

Inspecting the Polished Diamond


  • Mercury Diamond is a "diamond pricing consultancy founded by Ehud Laniado" that features more than 18,000 prices for polishing and cutting a diamond.
  • The cost of polishing a diamond varies based on its color (from D to M), clarity (from SI2 to IF), and the shape (round, semi-round, or square).
  • For instance, diamonds between 10 and 15 carats that are SI2 cost between $8,300 and $30,400 per carat to polish while those that IF, or internally flawless, cost between $13,900 and $113,800 per carat to polish.
  • The polishing prices for 15 to 20 carat diamonds are similar to the 10-15 carat ones, with SI2 diamonds costing between $10,300 and $37,900 per carat while the IF diamonds cost between $16,700 and $122,500 per carat.

Proposed next steps:

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In our initial research, we were able to detail the different steps of cutting and polishing of a diamond, including the price for a 10-20 carat unpolished diamond. As this process was detailed above, we propose to continue our research into how artificial diamonds are created in a lab. We will provide One: the material(s) used to make artificial diamonds, Two: the name and a description of each step in the process of creating artificial diamonds. Three: Details on how lab created diamonds are certified and graded, Four: the estimated price for the creation of an artificial diamond, and Five: the names of 1-2 labs that are creating lab-grown (man-made) diamonds.
We could also identify 4 top diamond polishing companies that specialize specifically in cutting and polishing diamonds. Top will be determined by their revenue or consensus from industry experts/reports. For each company, we will provide an overview of its services, its revenue, the pricing for cutting and polishing a diamond, 3-4 examples of notable customers, any variation in the process they use for cutting and polishing a diamond, and their competitive advantage. Our focus will be global as most of the companies that do that seem to be situated in Asia.