Moonstone and labradorite are two common and very popular types of the feldspar mineral group, beloved for the optical phenomenon of “schiller”: a colorful glow originating just below the surface of the stone. Often, these stones are polished into flat cabochons to be set into bezeled rings and pendants. Quality material is difficult to find in bead form, partially due to the fragility of the stones: despite being a 6 on the Mohs hardness scale, feldspar has perfect cleavage and will chip and break easily under misapplied pressure. When using feldspar in jewelry, I stick to earrings and necklaces.
When I’m looking for an white tone with intriguing elegance, I choose moonstone.
Highest quality moonstone is nearly transparent, and exhibits vivid iridescence from many angles.
Most available labradorites exhibit a greenish-yellow schiller. I prefer specimens that glow with the more rare blues, oranges or reds.