Amber, the fossilized resin of extinct trees, is one of the oldest gems known to man. Amulets made from it have been found in tombs dating from the Stone Age. Of rich color, its electrical properties made it magic to primitive man and this fascination has continued to the present day. Widespread trade in amber began over 9,000 years ago, when it traveled from the Baltic region to the palaces and cities of the ancient Mediterranean, such as Knossos and Mycenae. It was believed in Antiquity-- as now--that amber could cure numerous ailments and avert evil or prevent witchcraft. Ancient myths ascribed its origins to the rays of the setting sun, cooled in the ocean; to the tears of rare birds; or to the urine of the lynx. Homer makes mention of amber in the Odyssey. In prehistoric times, the resin oozing from trees sometimes encased insects and other specimens of natural life. These inclusions are highly prized today. Amber varies in color from pale yellow, to rich honey brown, to deep orange to red. Soothing to the touch as well as to the eye, it is still one of the most popular gems after the passage of millennia. For centuries, coral-- like pearl, a gift of the sea--was classed among the precious gems valued by man. Not strictly a mineral, coral is an organic substance, composed of the skeletons of millions of tiny marine animals. In its natural state, coral is plantlike in appearance and grows in warm water at depths of up to 90 feet. In hue, it varies from white, to pink, to red or orange, to black. Coral jewelry is known from the Egyptian, Biblical, Classical and Islamic periods. Coral is used as a heart stimulant, as an antidote for fevers and toxins in the body, and for preventing vomiting, colic, and childhood diseases. Its mysterious strength seems to derive from its organic source material, the accumulated energy of living things.