Usually very light in color--either white, pink, greyish or blue--chalcedony is a translucent or transparent cyrptocrystalline variety of quartz almost always used in cabochon form for gems. It is most commonly found in the deep recesses of volcanic rocks, and in antiquity the most prized variety came from Chalcedon in Bithynia in Asia Minor. The Egyptians, Romans and peoples of the Holy Land frequently carved intaglios into it, preferring the milky variety above all others. Medicinally, chalcedony is said to have the power to drives away fevers, to cure or prevent diseases of the eye (especially cataracts) and to aid in the relief of gall stones. It was one of the amuletic stones used by the ancients to banish bad dreams. Its colors are generally of the soothing variety, and those who chose to wear the stone are blessed with a peaceful and equable disposition.