1. The problem
2. Diamond Cut Study: goals, tasks, problems
3. Steps to development and application of a diamond cut grading system
4. Stage 1. Understanding of basic phenomena. Work with parametrical cut
5. The Viewing Conditions
6. Illumination
7. Stage 2. Basic Light Responses. Work with real diamonds
8. Stage 3. Master Stones for cut grading. Testing of human observation of diamond appearance
9. Conclusion
10. References

There is widespread agreement that the diamond industry has a need for a widely accepted and reliable cut grading system. Continual improvement of luxury goods that compete with diamonds has led to a growth in their share of consumers dollars. An advanced, but easily communicated, grading system will give the diamond industry a much needed impetus, but not only by way of creating better consumer confidence. The industry will gain more freedom in diamond cutting and this can lead to the creation of more beautiful diamonds and better profits.

Developing such a system that is acceptable and beneficial to all parties, is a complex task involving the optics of the stone as well as human taste and physiology. The implementation of such systems will require new approaches, technology and devices, as well as good communication and throughout all sectors of the industry.

Our presentation is devoted to the explanation of one methodology of diamond cut grading. In this methodology we avoid grading cut based on proportions and similar parameters. We will base our system on the optical responses of each diamond; this approach will allow the development of a universal system that will apply to all diamond shapes, and other gemstones.

Further more, this proposed system will lead to differentiation of market segments and of consumers groups.

Cut quality influences diamond beauty and value but the complexity of grading cut results in diamonds that are more and less beautiful falling into the same cell of a pricelist. To combat this, a lot of effort today goes into branding diamonds. Producing consistently beautiful new cuts can add value to branding efforts. However labs do not currently rate round diamond beauty, let alone compare and evaluate the beauty of different fancy shapes or new cuts. The short comings of current lab evaluation methods, via parameters (proportions and angles), reduces the economic need for diamond cutters to create more beautiful cuts.

Adding to the limitations of lab grading systems is the high cost of rough for empirical testing and experimentation. Development of our approach would also result in computer aided design technology to develop new cuts.

Is it possible that diamonds will be designed that are superior to diamonds considered as excellent or ideal today?

Evaluation task. Cut quality influences diamond beauty and value but the complexity of grading cut means more and less beautiful diamonds fall into one cell of pricelist.
Retail technology. Branding technology is used to gain a customer's trust concerning a given diamonds quality and beauty. Consistently beautiful new cuts will add value to such brands.
Fancy cut problem. The market can not evaluate and compare different fancy shapes.
Market for certified diamonds. The data on a certificate does not allow the evaluation of cut quality.
Grading system problem. Diamond beauty is currently evaluated via parameters (proportions and angles).
Problem of manufacturing. Diamond cutters can make better quality and create more beautiful cuts but their efforts are blocked by currently used grading systems.
Cut evolution problem. Cutters are restricted in empirical testing and develop more beautiful diamonds because of high cost of rough and because of limitations of the labs grading systems.
Lab problem in cut grading. Cut grading scales developed and used by labs result in diamonds being cut to proportions that they grade as excellent or ideal. What if progress in technology results in these diamonds no longer being considered as excellent or ideal? Will those certificates and the labs brand be depreciated?

Stage 1. Understanding of basic phenomena. Work with parametrical
diamond cut.
Stage 2. Basic Light Responses. Work with real diamonds.
Stage 3. Master Stones for cut grading. Testing of human observation of diamond appearance.
Stage 4. Cut grading system and cut grades development. Practical applications of cut grading for industry and trade.

Sergey Sivovolenko, OctoNus, Moscow, Russia
Yuri Shelementiev, Gemological Center MSU, Moscow, Russia