Moonstone

Moonstone, especially associated with Yin and femininity, has very characteristic bluish reflections called “adularescence”. This word comes from the first name of the stone, “adular stone”, in reference to Mount Adula, between Switzerland and Italy, where the largest deposit of moonstones was located in the eighteenth century.
In Greek mythology, moonstone was associated with the goddess of the night, Nyx. She was also the stone of Selene, goddess of the full moon. In America, the Sioux associated stone with the goddess Hanwi, “sun of the night”. It protected the Sioux during the night, especially from evil spirits.