The Moonstone has a milky white, luminous glowing appearance with different hues of blue and yellow. The gemstone, belongs to Feldspar group of minerals that make up 60% of the Earth’s crust. The majority of them comprise combinations of aluminum silicates of soda, potash, or lime and are all closely related in structure and composition. Feldspars are the main constituents of igneous and plutonic rocks.
The Moonstone’s name sums up common characteristics of all feldspars in that they all possess beautiful optical qualities of iridescence (lustre), aventurescence (glitter) and adularescence ( a milky white or blue sheen)
The Moonstone’s adularescence creates a white moonshine like shimmer that seems to float within the stone. This is caused by the gemstone’s layered structure. Known for its ethereal beauty, the moonstone is generally inexpensive, except for some of the rarer varieties.
The best and rarest moonstones are over 1 carat in size and are colorless, except for a beautiful deep blue sheen and high clarity. These characteristics are the determinants in how much the gemstone is valued.
Moonstones measure around 6 on the Mohs’ hardness scale, which means that they are medium hard. A level of care therefore needs to be taken when wearing them, as they can be easily scratched.
Moonstones have traditionally been cut as cabochons but can also be found with faceted cuts.
Sri Lanka has traditionally produced the highest quality Moonstones that have colors in light to medium silver blues and silver.
More than 40 feldspars have been identified, of which the Moonstone is only one. Some of the other feldspars that are used as gemstones are:
Labradorite – A semi-translucent gray with a broad iridescent color effect.
Sunstone – A yellow-orange translucent to semi-translucent gemstone with a golden sheen that resembles the Moonstone
Amazonite – An opaque greenish blue variety