Webster’s Unabridged Dictionary (Second Edition) defines a gem as “Any jewel, whether stone, pearl, or the like, having value and beauty that are intrinsic and not derived from its setting; a precious or, some-times, a semi-precious stone cut and polished for ornament.” Also, “A semi-precious stone of value because carved or engraved, as a cameo or intaglio.” Interestingly, below these definitions appears, “In modern usage, GEM more frequently suggests a precious stone as cut or polished; JEWEL, a precious stone as set and worn for ornament. . . .”
The professional view differs somewhat as expressed in the Gemological Institute of America’s Jewelers’ Manual (1964): “GEM. (1) A cut-and-polished stone that possesses the necessary beauty and durability for use in jewelry; also, a fine pearl. (2) An especially fine specimen; e.g., a gem diamond. In this use, the meaning depends on the ethics and the range of qualities handled by the seller. (3) As an adjective, a prefix; e.g., gem quality, gem crystal, etc. (4) As a verb, to decorate with gems.”
The definitions above agree that a gem must be beautiful and valuable, and that it must be cut and polished so that it can be used in jewelry. Webster’s definition includes engraved gems since these are made from suitable material and are cut and polished. In fact, until about the turn of the century, the word gem meant an engraved stone more than any¬thing else. Today the meaning has broadened until it embraces all kinds of cut stones, pearls, and even jewelry sets fashioned from organic materi¬als such as amber, coral, jet, and ivory. However, for size reasons, it can¬not apply to the large objects produced by the lapidary such as spheres, book ends, ashtrays, and carvings over an inch or two in length which are manifestly awkward to wear upon the person. However, it is emphasized that meaning (2) of the Jewelers’ Manual cited above is still very much in use in the trade, that is, the word gem means a superlative specimen, generally of superb color, of best internal quality, finely cut, and other¬wise head and shoulders above the vast majority of specimens cut from the same species. Thus the term “gem turquois,” as an example, refers to the finest grade of Persian material, i.e., pure uniform blue of the highest possible intensity, and free of any defect whatsoever.
In this catalog, the term gem will be used principally to denote finished stones ready to wear in jewelry, but it will also be used in the sense of top quality as defined above. On the other hand, the term gemstone, or, simply, rough, will be used only to designate rough material which has not had any lapidary work expended upon it.
The term precious stone, introduced above, now needs defining. At one time it was used in a narrow sense to signify one of a few very hard, durable, and beautiful minerals of considerable rarity which traditionally had enjoyed the highest esteem since antiquity, i.e.:
Diamond Chrysoberyl
Corundum (Ruby and Sapphire)
Opal
Beryl (Emerald)
Pearl
Despite the fact that pearl is not a mineral, it was commonly ranked as a precious stone and included in the above list. All other gemstones were arbitrarily classed as semi-precious stones, a term which is rapidly losing favor because it is essentially meaningless. This becomes clear when one considers the very high prices for large specimens of superior quality which certain so-called “semi-precious” stones such as demantoid (andradite) or benitoite can command. While they may not be as durable or as beautiful in some respects as the classical “precious” stones listed above, they nevertheless are in demand as collectors’ items. Also it is true that diamonds, rubies, sapphires, and other “precious” stones occur in poor specimens, which, in some instances, sell at much lower prices than those considered to be of lesser rank. It is largely for these reasons that the designations “precious” and “semi-precious” are being discarded.
Another term which is also losing ground but which has more to say in its favor is ornamental gemstone. It was coined as a classification for the massive or rock-like gemstones which found major employment in objects larger than jewelry gems, although some could be fine enough in quality to fall into the latter category. Included were such minerals as malachite, rhodonite, serpentine, jadeite and nephrite, chalcedony, and a number of others. Again the distinctions between such massive gem¬stones and others of higher rank are poorly defined and it is not at all uncommon to see fine examples of each of these minerals employed in jewelry as cabochons, small pendant carvings, beads, cameos, etc.
Another category of gemstones which is still in use is that of rare or unusual gemstones, generally meant to include those gemstones which occur so infrequently in gem quality that they are scarcely known except
to connoisseurs. Here are included andalusite, axinite, cassiterite, iolite, and kornerupine, among others, all of which are reasonably durable and, in the better examples, quite attractive. In the last several decades a much greater number of species has been added to this category, including those gemstones which by no stretch of the imagination can be called “gemstones” if one of the criteria is to be durability when worn in jewelry.
Into this group fall such fragile species as amblygonite, apatite, beryllonite, dioptase, and sphalerite. Some are so soft or so readily cleaved that cutting them is a severe test of the lapidary skill. Because of their inherent weaknesses, they must be forever consigned to soft folds of padding in a gem paper or in a cushioned mount in an exhibit case, never to be set in jewelry except as an empty gesture.
Nevertheless, many of them are beautiful, and in terms of the amount of skill and effort expended on cutting them, they represent considerable value in a small package. Most of these species are cut by amateur lapidaries, particularly the more venturesome who become bored with cutting standard gemstones and eagerly seize the challenge of trying something new. Gradually these species are becoming acceptable to collectors, connoisseurs, and museums, and the demand for rough is increasing to fulfill a widening market for the finished gems.
Aside from the gemstones derived from the mineral kingdom there are those which owe their origin to organic creation. The most important example, touched on above, is the pearl. Pearls are concretions produced within shellfish and vary widely in shape and attractiveness, depending on which shellfish grows them. Their use in jewelry and ornamentation, at least among ancient civilizations accustomed to fishing in fresh or salt waters, may be even older than the use of mineral gemstones. By custom they have been considered as gemstones from time immemorial. Other organic materials classed as gemstones are mother-of-pearl, amber, coral, tortoise shell, ivory, and jet.
A final category of gemstones is one that is becoming increasingly important, namely, synthetics. Most synthetic materials are the laboratory equivalents of such valuable natural gemstones as ruby, sapphire, and emerald, but one, strontium titanate, has no known counterpart in nature, while another, synthetic rutile, has no natural match in respect to color and transparency. The commercial synthesis of gemstones and the creation of those without natural counterparts will probably increase as the necessary growth conditions are investigated and economical manu¬facturing techniques developed.
To summarize, there is no quick and easy definition for the term zemstone which is acceptable on all counts. It covers a wide range of materials, although most of them are minerals and rocks with only a few being organics. However, it is safe to say that ornamentation, whether it be of the person or otherwise, is the principal theme pervading our esteem of gemstones. Thus, when we think of gemstones, we think first of colorful and durable mineral materials obtained from the crust of the earth. This is the traditional restriction placed upon the term gemstone and accounts for the reluctance to accept into the fold a host of extremely attractive rare but soft minerals and organic materials beyond those few already mentioned.
Other special terms, such as cameos, intaglios, and faceted and cabochon gems, will be fully defined in later chapters. It is time to turn our atten¬tion to examing the factors which make gemstones valuable, for it is these which must be continually kept in mind if shrewd assessments of value are to be made.