Grading Vs. pricing part2

II. BALANCING QUALITY FACTORS

You have already understood to grade each quality factor separately. You can now judge the stone’s color, for example, and determine its effect on beauty in comparison to similar stones. The same is true of clarity and cut.

‘‘Quality is only one factor that affects price’’

Up to this point, however, you have learned each factors were equal but by now you probably know how rare it is to see two stones of the same variety that differ in only color or clarity or cut. Normally, when we compare the quality of the stones to determine relative value-in buying we must deal with differences in two or tree factors. Suddenly the effect of any one factor can no longer be isolated from effects of other two.

How do you add them all up? Color and clarity and cutting are a little like apples and oranges and bananas- you can’t just total them to get a definitive quality grade. It is a very sophisticated problem, since we know how dramatically each factor can affect the others. Clarity for example, can dictate cutting variations that hide inclusions. This may produce a less attractive cut but yield an overall improvement in the gem’s clarity appearance. Which is more significant in overall quality here-clarity or cut?

Good cutting can bring out best color while poor cutting can reduce color quality. Some inclusions can reduce color quality,  unintended color zoning                            (uneven color) can lower the clarity grade. Differences in the rarity and availability of different qualities of rough (uncut gemstone) in particular sizes can also modify the effects of the basic quality factors. So, as you can see, the impact of any one factor is not necessarily the same on every stone.

COLOR

With non phenomenal colored stone, color is the overriding factor. Certain colors are rare in some varieties, and hence more valuable than in others, and in any variety, truly dynamic color is rare; if the color is good, most people are willing to tolerate greater variations from the ‘‘ideal’’ in either of the other two quality factors.

‘‘Truly dynamic color is rare in any variety.’’

Conversely, with a lower color grade, our tolerance for the same variations in the other factors is considerably lower.

CLARITY

The effect of clarity varies, too. In certain verities, clarity may sometimes have a greater impact on the rank than small nuances of color. In emerald, for example, unincluded (clear) stones of any size with excellent color are rare, so a finished stone with a high clarity grade is really unusual. Add to this widespread differences in opinion about the effect of ‘‘invisible’’ versus eye-visible clarity characteristics on overall rank of a stone, and the situation becomes even more complicated.

CUT

Weight retention is a primary consideration in cutting expensive materials. A medium cut grade on a fine-colored ruby with a high clarity grade will lower its rank only slightly. With less expensive materials, however, cut has a much greater impact on rank, since getting large pieces of good rough is usually not a problem. Some lower quality stones of these materials almost ‘‘fall off the chart’’ due to the cut grade. Since amethyst rough, for example, is readily available in large sizes, cutters have no reason to compromise cutting quality in save weight. With amethyst, then, a medium cut grade has a greater impact on the overall quality of the stone, and lowers the rank.

CARAT WEIGHT

The Combined- Grade Analysis Charts do not show the effect of differences in weight. They cover specific weight ranges, which we will discuss in the next section. Weight is fairly easy to compare, because you can measure it directly with loose stones.