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.
30 ct ... Rainbow Moonstone Cabochon ... 21 x 16 x 6 MM
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.
Faerie Magic in Minerals. (Aluminium phosphate wavellite, High Down Quarry, Filleigh, North Devon, England. Discovered by John Hill late 18th c and named for William Wavell, a local physician and mineral collector.) // photo by Dave Green