Chalcedony is a semi-precious stone and a variety of the mineral quartz. The color is almost white to light blue or dove blue, often with stripes. The stone is also found in shades of apple green (called chrysoprase), pink, red (variety carnelian), brown (called sarder), and copper color. Sites are in Brazil, Madagascar, Uruguay, India, USA and Great Britain, among others. The clear blue chalcedony comes from Namibia and is becoming increasingly rare, so that the stone increases in value. In ancient times, statues of weather gods were carved from chalcedony. A number of medicinal properties are attributed to chalcedony, namely against hoarseness, tonsillitis, vocal cord problems, varicose veins. According to various literature, Chalcedony belongs to the zodiac signs Cancer and Sagittarius.