Chalcedony is a microcrystalline or cryptocrystalline quartz with a hardenss of 7 on the Mohs scale. It is found world wide and is commonly available.
Blue Chalcedony is a creative stone. Opening the mind for new ideas and helping to accept new situations. A stone for communication, aiding verbal dexterity, mental flexibility and enhancing listening skills. It is also said to improve the memory. It can also give one a feeling of lightheartedness and encourage optimism. Additionally it can enhance the immune system and have an anti-inflammatory effect.
In ancient times chalices wold be formed out of Chalcedony and lined with silver. They were said to prevent poisoning.