Gem Profile- Moonstone

Moonstone Facts

Geologically speaking, true moonstone is an orthoclase feldspar gem-rock that forms in combination with one or more related minerals, including albite, adularia, perthite, peristerite, or sanidine.

The first historically documented moonstone was the adularia variety, discovered in the Adula Mountains of Switzerland.

However, archaeological finds on the island of Sri Lanka, formerly known as Ceylon, show that beautiful moonstones were used long before modern documentation placed a name or claim on them.

Moonstone wire wrapped by Beverly Brown

Natural moonstone occurs in shades of white, bluish white, gray, silvery white, and occasionally pale orange or peach.

Some experts argue that only white stones with a blue sheen should be classified as true moonstone.

Most moonstone specimens contain fine, insect-like parallel inclusions known as "centipedes."

When well cut, a moonstone may display sharp eye effects and, in rare cases, a four-rayed star.

Most gem-quality moonstone belongs to the adularia variety, which exhibits a distinctive inner glow known as adularescence.

This effect creates a soft, milky blue sheen that appears to float across the surface of the stone, resembling moonbeams, which is how moonstone earned its name.

A peach moonstone that has been carved to resemble the "man in the moon." Private collection, Dale Armstrong.

Moonstone Sources and Imitations

Translucent adularia moonstone is most often found as water-worn pebbles eroded from pegmatite deposits.

In many mining areas, these gravels form layers between rock and soil and must be shoveled and hauled to moving water sources such as rivers or sluices.

The material is placed on screens so the dirt can be washed away, allowing moonstone fragments to be separated from the remaining debris. As a result, high-quality moonstone is rarely found in sizes that could be considered large.

Some of the most well-known moonstone sources are Sri Lanka, Burma, and India, where stones appear in soft pastel shades of pink, yellow, green, and white. In North America, moonstone is found in Ontario, Canada, and Virginia, while sanidine moonstone is a notable find in New Mexico.

Moonstone also occurs in Switzerland, Madagascar, Brazil, Kenya, and western Australia.

The most common imitation of moonstone is glass, often sold under the name opalite.

Chatoyant chalcedony is also sometimes mislabeled as moonstone.

Because the word selenite comes from a Greek term related to the moon, some people mistakenly believe moonstone can be called selenite. In reality, selenite is a completely different mineral belonging to the gypsum group, not the feldspar family.

A pair of calibrated peach-tone moonstone cabochons. Private collection, Dale Armstrong.

Moonstone in Culture

Moonstone in its many types and colors has been known and used by humans for centuries.

During the 1800s, white moonstones were especially popular in engagement rings.

Because most astronaut-controlled space flights have launched from Florida's Kennedy Space Center, including the mission that carried Neil Armstrong and Edwin Aldrin to the moon, Florida adopted moonstone as its state stone in 1970.

Moonstone was once known as the "traveler's stone," believed by some to offer protection during journeys.

It is also an alternate birthstone for June, along with pearl and alexandrite.

Moonstone Wrapped in Argentium and 14kt Gold Filled Wire by Jane Elizabeth Duke

Ancient cultures believed that the phases of the moon affected the adularescence of polished moonstone, reaching its peak brilliance during a full moon.

For those who value moonstone for metaphysical reasons, it is thought to carry balancing, lunar energy associated with new beginnings.

Moonstone is believed to clean

Carved Moonstone Faces wrapped in sterling silver wire by Tina Bowersox