Moonstone or "Adularia", an orthoclase feldspar, was originally named for an early mining site at Mt. Adular in Switzerland. From this tradition we derive the term "adularescence" which is the optical phenomenon of iridescence which creates a billowy, floating blue to white light in this gem. Adularescence is due to diffraction of light as it hits thin, alternating layers of orthoclase and albite within the gem.
Rainbow moonstone is from the feldspar family of minerals. Rainbow moonstone is white or clear, and at times has a pearl-like color. The rainbow moonstone has natural white inclusions. Sparkling glimpses of red, gold, blue, and green can be seen, hence the name “rainbow moonstone.” Tiny albite crystals within the stone provide a shimmering glow known as adularescence.
Moonstone is a very personal stone. It is a reflection of the person who owns it. It does not add or detract, only shows how it is. This is why the moonstone is said to perceive that which "is". Moonstone is foremost a talisman of the inward journey, taking one deep into the self to retrieve what is missing, the parts of the soul left behind or forgotten, then brought to light.