Florida State Gemstone
Moonstone is the popular name for a pearly and opalescent variety of feldspar, the most common mineral on Earth. Moonstone is the most valuable form of feldspar and is typically a potassium aluminum silicate. The most common moonstone is composed of gem-quality crystals of the mineral adularia. The stone occurs in numerous colors, including gray, white, off-white, peach, orange, green, and brown, but the most valuable is deep blue. Rainbow moonstone is milky white with a rainbow colored sheen.
Although moonstone is not found naturally in Florida, it was designated the official state gemstone in 1970 to commemorate American astronauts flying from Florida to the Moon in 1969. Until that time, all astronaut-controlled space flights had been launched from Kennedy Space Center in Florida.
Moonstone’s layers scatter light in many directions, producing an effect called adularescence. This shimmer, or moonlike glow, is a bluish-white and is what gives the stone its name. Another synonym for moonstone is selenite, from the Greek word for "moon."
FORMATION AND OCCURRENCE
Moonstones are composed of intermingled orthoclase and albite, two species of feldspar. As the newly formed mineral cools, it separates into thin, flat layers. The finest specimens of moonstone come from Sri Lanka, India, and Brazil.
Moonstone was an extremely popular gemstone in the Art Nouveau period. The French master goldsmith René Lalique, as well as many of his contemporaries, frequently used moonstone in jewelry design.
Moonstone is one of the more common gems. While not particularly expensive or rare, stones command a higher price when they have intense color and shimmer, are large, and are more transparent. To best display the gem’s light reflection, moonstone is most often cut as a cabochon. The very rare blue moonstones that display a great depth of color are the most expensive.
In India, it is believed that moonstone wearers will have beautiful dreams. Because the stone is considered a symbol of fertility in Arab culture, women in that part of the world often sew moonstones into their garments. The gem is also said to protect women and children, as well as bring good fortune, enhance passion, and balance yin and yang. Legend says that moonstone will ensure abundant crops. In early times, it was believed that one could see the future by holding a moonstone in the mouth during a full moon.
The stone is believed to help relieve backaches and headaches, promote digestion, and protect against epilepsy and sunstroke.
Moonstone is the birthstone for the month of June. It is the planetary stone for Neptune and Venus and the traditional stone for the 13th wedding anniversary.
Chemical Formula: KAlSi3O8
Crystal Structure: Monoclinic
Hardness (Mohs): 6+
Color: Can be numerous colors, including grey, white, pink, green and brown, but the most valuable are deep blue
Luster: Pearly and opalescent
Refractive Index: 1.520-1.525
Some data courtesy of the Mineralogical Society of America
Author: World Trade Press