Natural Blue Fire Every Bead - Labradorite Faceted Tear Drop Beads Strand Sold per 6 Beads & Sizes from 10mm to 14mm approx. Labradorite a feldspar mineral, is an intermediate to calcic member of the plagioclase series. Labradorescence is a side-effect of the molecular change which occurs in large crystal masses of anorthosite, producing an iridescent play of colors.