Among the rarer minerals that produce good gemstones are cordierite, benitoite, euclase, phenakite, beryllonite, willemite, wernerite, danburite, datolite, axinite, brazilianite, andalusite, sillimanite, kyanite, kornerupine, enstatite, diopside, epidote, sphene, sinhalite, and orthoclase. Willemite, a rare zinc silicate found in only a few localities, is typical of these rarer minerals. The famous zinc mines at Franklin, N. J., produced a few large gemmy crystals of willemite, and some fine gemstones were cut from some of these. Willemite’s borderline hardness of 5 to 5½ and its extreme rarity effectively eliminate it from the gem market, but the collector who is able to obtain a good stone of this material is indeed fortunate. [Illustration: Exotic gems that represent collectors’ items lie beside a 3¼-inch-long box of Russian lapis lazuli. The stones are (left row, from top) a 28-carat andalusite from Brazil, gift of Fred C. Kennedy, a 10-carat cordierite from Ceylon, a 29-carat apatite from Burma, and (right row) a 42-carat brazilianite from Brazil, a 13-carat euclase from Brazil, a 29-carat wernerite from Brazil, and a 61-carat orthoclase from Madagascar.] Some mineral species, although beautiful when cut, and prized by collectors, are entirely too soft, are too easily cleaved, or have some other physical weakness that renders them useless as commercial gemstones. Sphalerite, apatite, fluorite, calcite, cerussite, zincite, and hematite are included in this group. Sphalerite is typical; it produces brilliant and colorful gemstones that hold their own among other stones of great beauty. Unfortunately, this zinc sulfide, with a hardness of 3½ to 4, is so soft and cleaves so readily that it is very difficult to cut properly, and it cannot be used in jewelry. 7 SOME NOTABLE GEMS IN THE COLLECTION The Smithsonian’s collection of gems continues to grow and improve rapidly, and it changes character constantly as important new gemstones are added and less important ones are retired. Approximately one-third of the gems in the collection in 1965 are itemized in the following list. Included are some of the largest gems of each kind, some of the more interesting stones, and some small gems notable for the places from which they came. Though listed by species and size, some of the larger stones are not included, and neither are most cabochons, rough opal, beads, carvings, and spheres. The descriptions listed include, in order, weight in carats; color; popular name or other description, if any; place of origin; and U. S. National Museum catalog number and name of donor. Gems in the Lea and Roebling collections usually are indicated by the letters “L” and “R.”