The majority of polished gemstones being cut today have small flat surfaces places on them in a facet-cut style. The Sri Lankan sapphire shown here exhibits a mosaic of dark and light blues, violet, and grayish blue, as well as colorless areas and patches of reflection, all in a harmonious pattern. The beauty of gemstone such as this comes not only from the two-dimensional presence of color, but also from the balance of this three-dimensional mosaic pattern that the facets create. Our eyes capture the complete balance of the mosaic pattern in its entirely, and we perceive it as beautiful. The mosaic pattern is what creates the deep and full character that we see in gemstones.

The diamond pictured on the cover jacket of this book shows how the rainbow of dispersion adds further color to the mosaic pattern. A transparent and brilliant diamond with a good appearance will sparkle with dispersion as it is moved. Conversely, a cabochon-cut gemstone’s beauty lies in a pure color, a transparency that is as high as possible, and a pleasing appearance.

The value of polished gemstone should be determined by its degree of beauty. The slightest difference in beauty will translate into a large difference in quality, affecting value. It may seem difficult to gauge the level of something so elusive as beauty, but the gemstone business is built upon just that. The methods of judging gemstone value presented in this book are not applications of an analysis of color science or scientific theory.  Rather, they are based on the fundamentals of quality determination actually used in the gemstone-polishing locations. Remember that the classification of beauty is a general separation, and that distinctions are not along fine lines, but broad boundaries. The borders between adjacent beauty grades such as A and A, or A and B, are vague. However, when comparing grade S with B, or B with D (as with the rubies in the following page), the difference in beauty becomes apparent. The term “ Beauty Grade” does not refer to a strict, narrowly defined grade. Establishing master stones for comparison allows for a fairly consistent classification of beauty, but beauty always involves a degree of subjectivity, making precise separation impossible.


There are probably those people who are convinced that the beauty of gemstones is absolute, but that is not the reality. Just as nobody is perfect, there is no gemstone created by nature that possessed ultimate beauty. What we actually see are (1) gems that are brilliant and especially beautiful, (2) those that are beautiful, and (3) those that are lacking in beauty- and between each is an infinite distribution of varying qualities.

The beauty of gemstone is controlled by the quality of the rough crystal, and it is human polishing technology that brings out that beauty. Rough material that shows the potential for great beauty is very expensive, and only the most skilled lapidaries take part in polishing it. In the final analysis, the quality factors for rough material- hue, transparency, saturation of color, pleochroism, shape, color zoning, richness of color, inclusions, growth zones in the crystal, fluorescence, and so forth- combine with the overall appearance and brilliance that result from the cutting process to create the beauty of the finished gemstone.

It would be impossible to scientifically analyze and judge each and every factor that influences beauty. Such an attempt would be extraordinarily complicated, and even if it were possible to objectively quantity each factor, the overall sum would still not provide a determination of beauty. A judgment based strictly on numbers would differ from what is actually seen. For example, whether the presence or strength of fluorescence is a plus or a minus can only be decided on a case-by-case basis.

Even considering just the one aspect of fluorescence, it is impossible to judge its effect on beauty other than by direct visual observation. The same applies when considering inclusion. Negative crystals, silk, and fractures will have different effects on transparency, and even the same type of inclusion will affect beauty differently depending on the gem’s tone.

Some gemstones may be acceptable in all aspects of quality except for one, such as a lack of richness or strength in their color. In other words, there are gemstones that may score close to 10 on a scale of 1 to 10 when analyzed, yet only rate as a 2 in terms of overall beauty. Determining quality through the results of such as a quantities analysis is meaningless without a consideration of beauty. What is important in not the analysis of each individual factor, but the consideration of the gemstone as a whole. Again, the beauty of a faceted gemstone lien in the quality of the balance if the three-dimensional mosaic pattern that it exhibits