"According to Hindu mythology, moonstone is made of solidified moonbeams. Many other cultures also associate this gem with moonlight, and it’s easy to see why. Its internal structure scatters the light that strikes it, creating a phenomenon known as adularescence. The visual effect is reminiscent of the full moon shining through a veil of thin, high clouds.
Legends say that moonstone brings good luck. Many believed that you could see the future if you held a moonstone in your mouth during a full moon.

Adularescent moonstone was once called 'adularia.' The name originated with a city in Switzerland, Mt. Adular (now St. Gotthard), that was one of the first sources of fine-quality moonstone.

Great designers of the romantic Art Nouveau era, such as René Lalique and Louis Comfort Tiffany, featured the pale gem in custom jewelry. Moonstone was also a favorite among artisans of the Arts and Crafts era in the last half of the nineteenth century, who used it in handcrafted silver items.

During the 1960s 'flower child' movement, moonstone provided its wearers with the desired ethereal look, and designers of the 1990s New Age movement again turned to moonstone’s natural beauty for inspiration."


Source: https://www.gia.edu/moonstone
"Moonstone is said in crystal healing to help calm responses and stress, and avoid overreaction. It brings hope, enhances feminine energies, sensitivity, intuition, and psychic abilities. It is also said to bring strong energies of abundance to one's life.

Moonstone is a stone of protection, especially during childbirth, pregnancy, and travel at sea. It is a stone of calm and relief from emotional stress. It is also associated with love of all kinds.

Physically moonstone is used in crystal healing to aid the pituitary gland and digestive system, obesity, water retention, hormonal problems, menstrual problems. Note that healing crystal meanings are spiritual supports to healing and are not prescriptions or healthcare information.

Moonstone is also used as a stand in for pearl, when pearl is not available. Moonstone is associated with the crown and third eye chakras, and sometimes with the heart chakra."

Source: http://meanings.crystalsandjewelry.com/moonstone/