Alexandrite Cats Eye Faceted Half Strand Rondell Beads | 3 mm | Green | 100 Beads |Green Alexandrite Faceted Half Strand Rondell Beads for Jewelry Making' Rare Green Natural Cats Eye ALEXANDRITE Sparkling Faceted Strand! The color is a beautiful opaque sea green with a blue color chatoyance! Often described as "emerald by day, ruby by night," alexandrite is a rare variety of the mineral chrysoberyl that changes colors from greenish blue in daylight. The shifting colors are the result of alexandrite's uncommon chemical composition