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News : Press release
Press Release Tuesday 15th March 2005
Cut Grade Master Stone Set co-operation ceases

In May 2004 HRD and OctoNus Cut Group announced they were negotiating a heads of agreement to pursue a joint study to create a Master Stone Set (MSS) to test and establish the uniformity of any or all diamond Cut Grade systems. It was intended that HRD would hold this MSS in perpetuity.

The two parties have not made an agreement and have decided to proceed independently of each other. No joint work had begun.

Related stories:

Diamond manufacturers, labs or other interested parties who would like to become involved with the OctoNus Cut Groups ongoing activities should contact Mr. Garry Holloway on or Mr. Sergey Sivovolenko on

New strategies of OctoNus technologies in the Cut Study area:

a) The primary goal is to work for cutters because they are the market for grading
  1. Create semiautomatic tools for the development of new cuts and their appraisal using OctoNus Basic Light Return (BLR)* and ETAS technology.
  2. Search for the best yielding combinations of parameters for existing cuts. Use this data in rough diamonds software's for marking software
    • 1st stage - introduce HCApro
    • 2nd stage - correction of HCApro based on OctoNus BLR
    • 3rd stage - develop the best marking technologies for princess and other fancies
  3. Help cutters to use deviations from ideal symmetry to gain the maximum yield, but still achieve Ideal Cut grades for any grading system.

b) Firstly we need to know that laboratories will grade new good cuts as good, and new bad cuts as bad

  1. If it accomplished without our collaboration, then we will be satisfied
  2. We allow any laboratory to create grading systems using our commercial products for themselves
  3. Laboratories may choose to create this system jointly (using OctoNus' proprietary and not available commercial products).
    • There is a big difference between BLR for cutters and a Cut Grade for customers. A Cut Grade must appraise each real stones base optical characteristic's that arise because of deviations from ideal symmetry and variations of parameters. But Cutters need precise technological instructions on producing a stone of maximum size and, simultaneously, raise the probability of the highest Cut Grade (taking into consideration the accuracy of the process control cutting quality of cutting at the factory).

* Examples of BLR:

  • Light return to the observer's eye
  • Light leakage though the pavilion
  • "Nail head" & "Fish eye"
  • Fire or colored light returned
  • Contrast or pattern
  • Scintillation

Individual BLR values for each and every diamond are characterized by its cut; they can be good to bad or positive to negative. We know that some diamonds can have good performance for one type light response and not so good for others.

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