The month of June actually has 3 stones considered to be its birthstone. One of them is moonstone. Moonstone is considered a "modern birthstone" by the American National Association of Jewelers in 1912.
Moonstone is part of a family of gemstones known as feldspar. They range in clarity from semi transparent to opaque and you can find them colorless, and in colors such as mocha brown, yellow, pink, blue, white, orange or peach, gray, green, or silver.
Rainbow moonstone is an opalescent gem that has a white or blue sheen or shimmer that it reflects under certain lighting conditions. This shimmer looks like the stone has a glow from within. This glow is called adularescence. The most highly valued rainbow moonstones would be colorless,
semitransparent to nearly transparent, without visible
inclusions, and a vivid blue adularescence, also known as blue
Along with adularescence, some moonstones show chatoyancy, also called the cat’s-eye effect. I have found this more in the peach and gray shades of the moonstone.
Around 100AD, moonstone was used in jewelry by the Romans who believed that the stone was formed by the light of the moon. In India, moonstone is considered a sacred and magical stone. It is believed to bring good fortune, enhance passion, protect women and children, mothers and babies, and to balance the emotions. A gift of this stone is symbolic of health and longevity. Moonstone was very popular during the early 20th century and was used extensively in art nouveau jewelry.
Moonstone is not very durable or hard gemstone compared to other gems used for jewelry. Use a bit of caution and care in handling this gem or a piece of jewelry with this gem in it. Do not use any harsh chemicals or cleaners to clean your gems.
Avoid using ultrasonic cleaners or steamers. Simply use a mild soap and a
soft cloth to clean your gemstones. Rinse well under warm water your
gemstone to remove any soapy residue. Moonstone is considered sensitive
to pressure, so do not set your stones using tension-style mountings.
Always remove moonstone jewelry before exercising, playing sports or
performing household chores. When storing your moonstone, store them
separately and away from other types of gems and jewelry, whether harder
or softer. If possible, wrap your stones individually using a soft
cloth, or you can place them inside a fabric-lined jewelry box for added
The highest quality moonstones are found in Sri Lanka and India.
Other notable sources include Australia, Brazil, Germany, India, Myanmar
(Burma), Madagascar, Mexico, Norway, Switzerland, Tanzania, and the
United States. Rainbow moonstone can be found in Brazil, Europe, India, Australia, Germany, Madagascar, Mexico, Myanmar, Tanzania, and Pennsylvania and Virginia in the U.S.