Mineralogy described Chalcedony as a cryptocrystalline and a fine-fibrous variety of quartz. It was named after the ancient city of Chalcedon located in present-day Turkey, on the shore of the Marmara Sea. This gemstone was used already in the Stone Age. It has a great hardness (6.5 to 7 on the Mohs scale).
It can assume a wide range of colours, but the most common colour varieties are: plain chalcedony (grey-white to grey), Chrysoprase (green), Sarder (yellow-brownish to brown), Carnelian (red to orange-red) and others.
The Chalcedony occurs in many places in Bulgaria, the most beautiful specimens are found near Kardzhali. It fills pores and cracks in the volcanic rocks or builds deposits on organic remains in carbonate rocks.
Many ancient cultures believed that the Chalcedony protects seafarers, repels evil spirits and cures depression or sadness.
People used it also for healing purposes against fever or to remove gallstones. They believed the Chalcedony can keep away the "bad eyes", which according to ancient people are major cause of diseases.
In lawsuits it helps to reach a favourable outcome. The Chalcedony can repel any external negative vibrations and absorb only the positive. It attracts luck, gives clarity of mind and dispels illusion.