Moonstone is formed out of the rock-forming mineral known as feldspar.
Specifically, the moonstone gem comes from orthoclase feldspar, and its unique mineral makeup allows it to take on a glowy light-reflecting quality that mimics moonlight.
This otherworldly sheen is known as adularescence, which is an optical effect that’s unique to moonstone.
In simple terms, adularescence is the light refraction that occurs when light hits the layered, scaled structure of the stone and creates a soft play of shimmering color.
The description of a play of color across a milky-white stone might sound similar to an opal gemstone. But the important visual difference is the hovering, diffused appearance in the moonstone, as opposed to flecks of color that appear embedded within an opal stone.
Here’s a quick tip: Picture the reflection of a full moon over the surface of a calm, quiet body of water. The effect of that floating blue light is exactly where the moonstone got its name!
The most valuable kind of moonstone by far appears completely transparent while also showing off a glowing blue light on its surface.
This precious variety, also known as the blue moonstone, is native to Myanmar and Sri Lanka. But today, it’s extremely rare. According to experts at the International Gem Society, this coveted type of moonstone has been mostly mined out.
Most moonstone colors currently available have an opaque, milky appearance but still possess that mysterious floating-light quality from the visual play of color. This type of moonstone gemstone is often referred to as a “white moonstone.”
One moonstone crystal variety that’s gained popularity is known as the “rainbow moonstone.” While a classic moonstone features a blue sheen, the rainbow moonstone is more prism-like in appearance and often features green and orange hues along with blue.
The rainbow moonstone is closely related to standard white moonstones, but it doesn’t technically belong in the same gemological category.
Rainbow moonstone is a transparent mineral that belongs in the feldspar mineral family, but it’s a different variety of feldspar than moonstone.
Peach moonstone occurs when there’s a higher level of aluminum within the moonstone’s crystal structure. It features a beautifully soft peachy-brown tint. Pink moonstone has a more rosy hue and often has more visible inclusions.
Black moonstone is a rare and unique variety native to Madagascar. It has a dark, opaque hue with a silver reflect. Because of its deep color, it’s often used to ward off negative energy.
Moonstone meaning and cultural and historical significance
Evidence of moonstone jewelry dates back to ancient times. Romans highly valued it because they believed that the moonstone was the solid form of fossilized moon rays!
Other associations of the precious stone with the moon itself led to its strong connection with lunar energies and deities worshipped by people of ancient civilizations.
For example, another name for this semi-precious stone is “selenite.” This word is taken directly from the name Selene, the Greek goddess of the moon.
Traditionally, the moon is associated with all things feminine—fertility, pregnancy, childbirth, romantic love, and feminine energy in general. Moonstones fit perfectly into this timeless tradition and are often prized for their contribution to female empowerment.