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GEMSTONES by Gordon T

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GEMSTONES by Gordon T GEMSTONES By Gordon T. Austin Webster's dictionary defines a gem as "any physical, and chemical properties as the natural Consumption jewel, whether stone, pearl or the like, having material that they represent. Synthetic value and beauty that are intrinsic and not gemstones produced in the United States Consumption of domestic gemstones was in derived from its setting; a precious or, include alexandrite, coral, diamond, emerald, the manufacture of jewelry, for exhibit in gem sometimes, a semiprecious stone cut and garnet, lapis lazuli, quartz, ruby, sapphire, and mineral collections, for decorative purposes polished for ornament. A stone of value spinel, and turquoise. Laboratory grown in statuettes, vases, and other art objects, and because it is carved or engraved, as a cameo or simulants have an appearance similar to that of certain industrial applications. intaglio." Additionally, the dictionary states a natural gem material but have different that gemstone or gem material is a stone or optical, physical, and chemical properties. The material from which a gem may be cut. So a gemstone simulants produced in the United Prices gem, gemstone, or gem material may be States include coral, cubic zirconia, lapis lazuli, described as inorganic or organic minerals used malachite, and turquoise. Additionally, certain Demand, beauty, durability, rarity, freedom for personal adornment, display, or to colors of synthetic sapphire and spinel, used to from defects, and perfection of cutting decide manufacture objects of art because they possess represent other gemstones, would be classed as the value of a gem. In establishing the price of beauty, rarity, and durability. simulants. Colored and colorless varieties of gem diamond, the CSO's control over output cubic zirconia are the major simulants and prices of diamond rough also is a major Production produced. In 1994, the reported value of factor. (See tables 4 and 5.) production of U.S. synthetic and simulant In 1994, the value of natural gemstones materials was $22.2 million. (See table 2.) Foreign Trade produced from deposits in the United States Fourteen firms, four in California; four in was $50.5 million. Production of gemstones, in Arizona; and one each in Michigan, New During 1994, the total value of all gemstones order of importance, included faceting rough, Jersey, New York, North Carolina, Ohio, and exported and reexported was about $2.24 lapidary rough, carving material, specimen Washington, produced synthetic and simulant billion, diamonds accounted for 87% of the material, natural and cultured freshwater pearls, gem material. Production included the total or $1.94 billion, while cut diamonds mother of pearl, saltwater pearls, shell, fossil manufacture of alexandrite, amethyst, accounted for 78% of the total or $1.74 billion. ivory, amber, and coral. In 1994, all 50 States azurite/malachite, cubic zirconia, emerald, lapis, The value of exports plus reexport of natural produced at least $1,000 worth of gem ruby, sapphire, and turquoise. The States in rough colored gemstones was about $29.5 materials. Ten States accounted for 93% of the descending order of value of production were million and the value of exports plus reexports total value of production of natural gemstones. California, New York, New Jersey, of cut natural gemstones was about $198 The States, in order of declining value of Washington, Arizona, Michigan, New Mexico, million. Synthetic rough and cut exported plus production, were Tennessee, Arkansas, and Ohio. reexports for the year were valued at $14.0 Alabama, Kentucky, Arizona, Montana, The U.S. Bureau of Mines estimates U.S. million and $12.9 million, respectively. Oregon, California, and Utah. Certain States production from the "Natural and Synthetic Exported and reexported natural and cultured were known best for the production of a single Gem Material Survey," a voluntary survey of pearls were valued at $1.02 million and $6.13 gem material (i.e., Tennessee for freshwater U.S. operations, and from Bureau estimates of million, respectively. During the year $34.4 pearls and Arkansas for quartz). Other States unreported production. Of the 387 operations million of coral and shell was exported and produced a variety of gemstones. Tennessee, surveyed, 84% responded, 84% of the natural reexported. Arkansas, Alabama, and Kentucky, in declining gemstone producers and 95% of the synthetic The value of gems and gemstones imported order of value of production, were the major and simulant producers. The Bureau estimated increased 12% to a record high $6.44 billion. producers of freshwater mussel shell and pearl. the production by nonresponding operations, by The value of imported gem diamonds accounted Arizona produced the greatest variety. professional collectors, and by amateur or for about 89% of the total. (See tables 6, 7, 8, Production included agate, amethyst, antlerite, hobbyist collectors. The basis for these 9, and 10.) azurite, chrysocolla, fire agate, garnets, jade, estimates was information from published data, malachite, obsidian, onyx, peridot, petrified conversations with gem and mineral dealers, World Review wood, precious opal, shattuchite, smithsonite, analyses of gem and mineral shows and sales and turquoise. California, Idaho, Montana, and statistics, and from information informally Diamond sales by De Beers Centenary AG North Carolina also produced a variety of supplied by collectors. was $4.3 billion in 1994, a decrease of 2.7% gemstones. Historically, North Carolina is the The value of production by individual compared with 1993 sales of $4.4 billion. Sales only State to have produced all four of the gemstone can be reported for those materials during the first half of 1994 were $2.6 billion, major gems: diamond, emerald, ruby, and that have three or more producers and if one 4% more than the $2.5 billion for the first half sapphire. (See table 1.) producer does not account for more than 75% of of 1993, second half of 1994 sales were only Laboratory grown synthetic gemstones have the total or if two do not account for 95% or $1.7 billion, 8% less than the $1.8 billion sales essentially the same appearance and optical, more of the production. (See table 3.) for the second half of 1993. De Beers controls 1 about 80% of the rough, uncut diamonds sold in Summaries. the world. During the past 5 years De Beers Mineral Facts and Problems, 1985. annual sales were: 1994, $4.25 billion; 1993, Mineral Industry Surveys, Annual Advance $4.40 billion; 1992, $3.42 billion; 1991, $3.93 Summary Supplement: Directory of billion; and 1990, $417 billion. During the Principal Gem Stone Producers in the same period De Beers' stocks of diamonds were: United States, 1993. 1994, $4.38 billion; 1993, $4.10 billion; 1992, $3.36 billion; 1991, $3.03 billion; and 1990, Mineral Industry Surveys, Annual Advance $2.68 billion. During 1994 was the first time Summary Supplement: An Overview of ever that De Beers' stock of diamonds were Gemstone Production in the United States. greater than its annual sales of diamonds. Sales of colored stones remained strong. Natural diamond production occurs in Africa, Asia, Australia, and South America. The principal producing localities are as follows: in Africa—Angola, Botswana, Namibia, the Republic of South Africa, and Zaire; in Asia—Russia (northeastern Siberia and in the Yakutia); in Australia; and in South America—Venezuela and Brazil. (See table 11.) Foreign countries in which major gemstone deposits (other than diamond) occur are Afghanistan (beryl, kunzite, ruby, tourmaline); Australia (beryl, opal, sapphire); Brazil (agate, amethyst, beryl, kunzite, ruby, sapphire, tourmaline, topaz); Burma (beryl, jade, ruby, sapphire, topaz); Colombia (beryl, sapphire); Kenya (beryl, garnet, sapphire); Madagascar (beryl, rose quartz, sapphire, tourmaline); Mexico (agate, opal, topaz); Sri Lanka (beryl, ruby, sapphire, topaz); Tanzania (tanzanite, garnet, ruby, sapphire, tourmaline); and Zambia (amethyst, beryl). OUTLOOK World demand for gem diamond can be expected to rise because of increasing effective personal incomes and the populations of the United States and other industrialized countries. Also demand will increase because of highly effective promotional efforts. These promotions are changing social customs in many eastern countries, particularly the use of diamond engagement rings. The changes are resulting in significant growth in the diamond market. Demand for other precious gems will continue to grow as diamonds become more expensive and the popularity and acceptance of colored gemstones increase. Demand for synthetic and simulant gemstones for both personal and industrial consumption is expected to increase. The diversity of sizes, types, uses, and values of gems and gemstones precludes any meaningful forecasting of future demand. OTHER SOURCES OF INFORMATION Bureau of Mines Publications Gem Stones, Ch. in Mineral Commodity 2 TABLE 1 GUIDE TO SELECTED GEMSTONES AND GEM MATERIALS USED IN JEWELRY May be Practical Specific Refractive confused Recognition Name Composition Color size1/ Cost2/ Mohs gravity Refraction index with- characters Amber Hydrocarbon Yellow, Any Low to 2.0-2.5 1.0-1.1 Single 1.54 Synthetic or Fossil red, green, medium pressed, resin, blue plastics soft. Beryl: Aquamarine Beryllium Blue-green Any Medium 7.5-8.0 2.63-2.80 Double 1.58 Synthetic Double aluminum to light to high spinel, blue refrac- silicate blue topaz tion, refrac- tive index. Bixbite do. do. Small Very 7.5-8.0 2.63-2.80 do. 1.58 Pressed Refractive high plastics, index. tourmaline Emerald do. Green Medium do. 7.5 2.63-2.80 do. 1.58 Fused emer- Emerald ald, glass, filter, tourmaline, dichroism, peridot, refractive green garnet index. doublets Emerald, do. do. Small High 7.5-8.0 2.63-2.80 do. 1.58 Genuine Flaws, brilliant, synthetic emerald fluorescence in ultraviolent light. Golden do. Yellow to Any Low to 7.5-8.0 2.63-2.80 do. 1.58 Citrine, (heliodor) golden medium topaz, glass, doublets Goshenite do. do. Any Low 7.5-8.0 2.63-2.80 do.
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