Never more popular, the Alexandrite halo rings feature a beautiful gemstone surrounded by sparkling diamonds. A pair of created alexandrite earrings is like two gifts in one. Blue-green by day, and purple-red by night, the color change of this gem is sure to please. A pair of created alexandrite earrings is like two gifts in one. Blue-green by day, and purple-red by night, the color change of this gem is sure to please.