The National Gem Collection had its beginning in 1884 when Prof. F. W. Clarke, then honorary curator of the Division of Mineralogy, prepared an exhibit of American precious stones as a part of the Smithsonian Institution’s display at the New Orleans Exposition. The same collection was displayed at the Cincinnati Exposition the following year. Between 1886 and 1890 the growth of the collection was slow, but in 1891 most of the precious stones collected by Dr. Joseph Leidy of Philadelphia were obtained, and these, combined with those already on hand, were exhibited at the World’s Columbian Exposition at Chicago in 1893.
Great stimulus was given the collection in 1894 when Mrs. Frances Lea Chamberlain bequeathed the precious stones assembled by her father, Dr. Isaac Lea. Her husband, Dr. Leander T. Chamberlain, who in 1897 became honorary curator of the collection, contributed a large number of specimens and, upon his death, left an endowment fund. The income from that fund has been used to steadily increase the collection over the years. Extremely rare and costly gems suitable for exhibition are beyond the income derived from the Chamberlain endowment, but this gap has been filled by many important donations, the most notable being the gift of the Hope Diamond by Harry Winston, Inc., New York City. Thus, from modest beginnings in 1884, there has been accumulated the magnificent collection of gems belonging to the people of the United States. The collection is displayed in the Smithsonian Institution’s great Museum of Natural History.
Left to right: 42-carat brazilianite, 8.4-carat euclase, 7.6-carat benitoite, 12-carat willemite, 20-carat amblygonite, and 16-carat orthoclase. (About two-thirds actual size.)
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THE STUDY OF GEMS
To the average person it might seem that a jeweler’s showcase of gems presents innumerable kinds of precious stones, when actually only a few species of minerals are there. Perhaps only diamond, ruby, emerald, aquamarine, sapphire, opal, tourmaline, and amethyst would comprise the entire stock. Yet, since the mineral kingdom consists of about 2000 distinct species, it would seem that a few more kinds of gemstones would be available. Certainly, many more minerals than are seen displayed by the jeweler have been used as gems over the centuries. The study of all these species of gem minerals constitutes modern gemology—a specialized branch of the science of mineralogy.
With the few exceptions already noted, all gems are minerals found in the earth’s crust. A mineral is a natural substance having a definite chemical composition and definite physical characteristics by which it can be recognized. However, for a mineral to qualify as a gem it must have at least some of the accepted requirements—brilliance, beauty, durability, rarity, and portability. Of course, if a gemstone happens to be “fashionable” it will have additional importance. Rarely does a single gem possess all of these qualities. A fine-quality diamond, having a high degree of brilliance and fire, together with extreme hardness and great rarity, comes closest to this ideal, and in the world of fashion the diamond is unchallenged among gems. The opal, by contrast, is relatively fragile, and it depends mainly on its rarity and its beautiful play of colors to be considered gem material.
When a gem material, as found in nature, has at least a minimum number of the necessary qualities, it is then the task of the lapidary, or gem cutter, to cut it and polish it in such a way as to take greatest advantage of all its possibilities for beauty and adornment.
PHYSICAL CHARACTERISTICS OF GEMSTONES
When a gemologist or a gem cutter examines an unworked mineral fragment (called rough) he looks for certain distinguishing characteristics that will aid him in identifying the mineral and in determining the procedures he should use in cutting it.