Chalcedony is a translucent to transparent milky or grayish quartz with distinctive microscopic crystals arranged in slender fibers in parallel bands. Chalcedony is a finely crystallized or fibrous quartz that forms rounded crusts, rinds, or stalactites in volcanic and sedimentary rocks. Chalcedony occurs in many forms, colors, and shapes. Chalcedony, agates, jaspers, bloodstone, cornelian, onyx, and chrysoprase all make up the chalcedony gemstones. The better known varieties of Chalcedony are: carnelian, sard, plasma, prase, bloodstone, onyx, sardonyx, chrysoprase, thundereggs, agate, flint, chert, jasper, petrified wood and petrified dinosaur bone. The colors of Chalcedony vary and can be pale blue, yellow, brown or gray with nearly wax like luster. Chalcedony is one of the gemstones, that used in commesso, or the florentine mosaic. It is a technique of fashioning pictures with thin, cut-to-shape pieces of brightly colored, semiprecious stones. Being an inexpensive stone, Chalcedony is the best available and most collected gemstone. Having good healing and mystic powers, the gemstone is believed to banish fear, depression, reduce fever and is believed to be excellent for eyes. Chalcedony is found in many parts of the world, but the most prized Chalcedony are from India, Madagascar, Burma, Brazil, Mexico & USA. Semi Prec