LESSON XIX
THE NAMING OF PRECIOUS STONES
Owing to the confusion which may result from a lack of uniformity in the naming of precious stones, it is very desirable that jewelers and stone merchants inform themselves in regard to the correct use of the names of the gems, and that they use care in speaking and in writing such names.
As nearly all precious and semi-precious stones are derived from a relatively small number of mineral species, as we saw in [Lesson XVIII.], and as the science of mineralogy has a very orderly and systematic method of naming the minerals, the best results are had in the naming of gems when we use, as far as is possible, the language of mineralogy.
Ancient Usage. Long established custom and usage, however, must be observed, for any system of naming must be generally understood in order to be useful. Thus the proper name for blood red, crystallized oxide of aluminum, of gem quality, according to the mineralogical system of naming, would be red corundum, but that same material is referred to in the Old Testament thus (in speaking of wisdom), "She is more precious than rubies." It is obviously necessary to keep and to use all such terms as have been for years established in usage, even though they do not agree with the scientific method of naming the particular mineral. It is, however, necessary that any name, thus retained, should be correctly used, and that it should not be applied to more than one material. Thus the term ruby should be reserved exclusively for red corundum, and not applied to other red minerals such as garnet, spinel, etc., as is too often done.
It will be the purpose of this lesson to attempt to set forth as clearly and as briefly as possible what constitutes good usage in the naming of the principal stones, and also to point out what incorrect usage is most in need of being avoided.
To cover the subject systematically we will adopt the order of hardness that we did in discussing mineral species in [Lesson XVIII].
Fancy Diamonds. Beginning with the hardest of all gems, the diamond, we have no difficulty as regards naming, as all specimens of this mineral, regardless of color, are called diamonds. When it is necessary to designate particular colors or tints, or differences in tint, additional names are used—for example, all diamonds of pronounced and pleasing color are called "fancy" diamonds in the trade. Certain of these "fancy" diamonds are still further defined by using a name specifying the color, as, for example, "canary" diamonds (when of a fine bright yellow), or "golden fancies," when of a fine golden brown, or "orange," or "pink," or "absinthe green," or "violet," as the case may be.
Names of Various Grades of White Diamonds. The great majority of the diamonds which come on the market as cut stones belong, however, to the group which would be spoken of as white diamonds, but many qualifying names are needed to express the degree of approach to pure white possessed by different grades of these diamonds. Thus the terms: 1, Jägers; 2, Rivers; 3, Blue Wesseltons; 4, Wesseltons; 5, Top Crystals; 6, Crystals; 7, very light brown; 8, Top Silver Capes; 9, Silver Capes; 10, Capes; 11, Yellows, and 12, Browns, describe increasing depth of color, and hence decreasing value in diamonds.