Centuries ago, peridot was known by the name topaz, since the stones came from Topazos, the island now known as Zebirget. The name topaz, as we have seen, is used today for an entirely different mineral species. SPODUMENE Spodumene, a lithium aluminum silicate, is one of the very few gemstones containing lithium. It has had more importance as a gemstone in the United States than elsewhere, a situation due to early discoveries of unique occurrences of a lavender-pink variety at Branchville, Conn., in 1879 and in San Diego County, Calif, about 20 years later. At the time of the discovery of the California material, the variety was named _kunzite_ in honor of G. F. Kunz, a noted American gemologist of the times. [Illustration: The 177-carat kunzite (at lower left) is a large flawless stone cut from California material of this variety of spodumene. It was given to the Smithsonian Institution by the American Gem Society. The other stones, all from Brazil, represent the more usual shades of spodumene. They weigh 327 carats (top left), 256 carats (top right), and 69 carats. (About half actual size.)] The finding of a bright green variety, _hiddenite_, in North Carolina about 1880 greatly stimulated the interest of American gem collectors. Some of the bright green spodumene coming from Brazil in recent years compares very favorably in color with North Carolina hiddenite. Other than in a scattered few of these unusual occurrences of kunzite and hiddenite, spodumene usually is found in yellow and yellow-green shades, with Brazil and Madagascar being the chief sources. [Illustration: This 880-carat kunzite from Brazil is one of the largest stones of its kind. (About actual size.)] Spodumene has a hardness of about 7, but with a refractive index of about 1.66 and a low dispersion there seems to be relatively little to recommend it as a gemstone. The fact that it exhibits a very strong tendency to cleave in two different directions would seem to rule it out completely as being too difficult to cut. Nevertheless, the production and purchase of cut stones of spodumene persist because of the beauty of the gem. The kunzite and hiddenite varieties of spodumene show strong _pleochroism_, or the ability to show three different colors when viewed in the direction of different axes. Some of the large Brazilian kunzite crystals mined in the early 1960’s have an intense rose-violet color when viewed along the long axis of the crystal but have pale blue-violet and pale tan colors when viewed from the other two directions. When heat treated, or exposed to strong light, this Brazilian kunzite loses its tan and bluish colors but retains the intense rose-violet. Because of spodumene’s pleochroism, the direction of cutting in the stones becomes extremely important, as it must be done in a manner that will take advantage of the violet color in kunzite and the green color in hiddenite.