Chalcedony (cal-see-doh-nee) is the name for a group of stones made of microcrystalline quartz. This just means that the quartz crystals are too small to be seen without high magnification. In the gem trade, chalcedony is usually used to describe the white, gray, light purple, or light blue translucent stones. The light blue and the light purple are the most popular colors. Chalcedony occurs in many different forms, colors and patterns and has been used in jewelry for centuries.
The varieties of Chalcedony are often named based on color. Agates are a multicolored variety of Chalcedony. Carnelian, aventurine and jaspers are also Chalcedony varieties. Chalcedony is well suited for jewelry with a hardness on the Moh scale of 6.5 to 7. It is a porous stone and is often dyed to enhance the color. The name comes from the ancient Greek town of Chalkedon in Asia Minor.
Chalcedony is found in many locations. Turkey is a good source for purple and blue stones, along with several different locations in Africa. There are also active blue and purple mines in the U.S.. It is also found in Brazil, Germany, Russia, Canada and Indonesia.
Because of the abundance and durability of Chalcedony, its usage goes back to as early as the 7th century B.C..The early Mesopotamians used it in seals and that practice was adopted by the Romans. It was also used as projectiles, knives and containers.
It is believed that Chalcedony aids in emotional balance, energy, generosity, charity and friendliness. It is also said to banish fear, depression, and touchiness. It is also thought to aid eyesight, reduce fever and stimulate creativity.
Light Blue Chalcedony