Blue is the rarest of the tourmaline colors. It is a peaceful and tranquil stone, and is often used to enhance psychic or intuitive abilities. It is a throat and third eye chakra supporting stone and aids communication of all kind, including mediumship.
From left to right, rings shown are:
Sz 6 small stone, Sz 6 medium stone, Sz 8 large stone, sz 7 medium stone