Sometimes the rarest beauty can be found in the most common materials. Feldspar is a volcanic mineral that can be found almost anywhere on earth. If you look closely at a piece of granite, you’ll notice that it often contains pink crystals. These pink granules are feldspar.
But not all feldspar is created equal. The variety known as Moonstone grew slowly in molten rock, alternating layers of orthoclase and albite. Each layer is about the thickness of a wavelength of light. The two minerals refract light differently and the result is Moonstone’s shimmering look, where light seems to billow across its surface. This effect is called adularescense, similar in effect to opalesence. Here’s a brief video from the Gem Institute that shows the effect:
In addition, moonstone can exhibit a cat’s eye effect, though this is less common.
Moonstones were popular in ancient Rome, because they were thought to be condensed moonrays. Romans and Greeks connected Moonstone with their lunar deities.
There is a common belief in India today that moonstone is sacred and magical. It’s thought to be a dream stone, bringing pleasant visions during the night. Whether you believe this or not, moonstone is a beautiful and interesting gemstone with a unique, lovely look.
One example of moonstones in my collection is this pair of earrings, with copper-colored moonstones set in 18K yellow gold with sapphires and pearls: