This report presents an overview of the production of specific gemstones from deposits within the
United States. The U.S. Bureau of Mines (USBM), Department of the Interior compiled and
analyzed the information contained in this report. The report should be viewed as a current "still
photograph" of a dynamic system. The information presented on a specific gemstones or for a
specific State can and will change with time. This overview presents historical and reference
information on the principal gemstones and their production in certain States. The report is not a
definitive work on gemstones within the select States or United States.
Webster's 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, sometimes, a semiprecious stone cut and polished for ornament. A stone of value because it is carved or engraved, as a cameo or intaglio." Additionally, the dictionary states that gemstones or gem material is a stone or material from which a gem may be cut. In short, a gem, gemstones, or gem material may be described as materials used for personal adornment, display, or objects of art because they possess beauty, rarity, and durability.
gemstones produced in the United States and other producing countries are of three types;
natural, synthetic, and simulant. The natural gemstones included minerals used as faceting,
lapidary, or carving rough, and specimen. Natural gemstones also include organic materials such
as amber, coral, fossil, ivory, mother of pearl, natural and cultured freshwater pearls, and natural
saltwater pearls. Laboratory grown synthetic gemstones have essentially the same appearance,
optical, physical, and chemical properties as the natural material that they represent. Synthetic
gemstones produced in the United States include alexandrite, coral, diamond, emerald, garnet, lapis
lazuli, quartz, ruby, sapphire, spinel, and turquoise. Simulants are laboratory grown gem materials
that have an appearance similar to that of a natural gem material but have different optical,
physical, and chemical properties. The gemstones simulants produced in the United States include
coral, cubic zirconia, lapis lazuli, malachite, and turquoise. Additionally, certain colors of synthetic
sapphire and spinel, used to represent other gemstones, would be classed as simulants. Colored and
colorless varieties of cubic zirconia are the major simulants produced.
U.S. gemstones production data are from different sources. The reliability and accuracy of the
data vary from source to source and even within the same source. The data are reliable for general
policy and economic decisions, but may not be applicable for site-specific or project-specific
The USBM collects U.S. gemstones production data from the "Natural and Synthetic Gem Material Survey," a voluntary survey of U.S. operations. Typically, the survey includes approximately 400 operations of which between 80% and 90% responded, accounting for more than 95% of the total production. Additionally, the USBM staff estimates unreported production by nonresponding operations, professional collectors, and amateur or hobbyist collectors. The basis for these estimates is information from published data, conversations with gem and mineral dealers, and analyses of gem and mineral shows and sales statistics. In the formal voluntary survey and the informal surveys, the USBM is dependent upon the cooperation and honesty of the producers, brokers, dealers, and collectors.
Value of natural gemstones produced from deposits within the United States for the past 5 years, by year are $51.1 million, 1993; $66.2 million, 1992; $84.4 million, 1991; $52.9 million, 1990; and $42.4 million, 1989. Production values for U.S. synthetic gemstones for the same period are $19.5 million, 1993; $18.9 million, 1992; $17.9 million, 1991; $20.5 million, 1990; and $18.8 million, 1989.