Alexandrite belongs to the Chrysoberyl mineral family (aluminate of beryllium) and contains Chromium, causing it to absorb light in different directions; the presence of Chromium differentiates it from other gems in the family. Alexandrite further has a color absorption band of 580 nanometres which falls in between the color absorption bands of an Emerald (550 nanometres) and Ruby (600 nanometres), enabling it to mimic an emerald during daytime and a ruby during nighttime.
Highly valuable Alexandrites have excellent clarity, possess a vivid bluish-green color during the day, and transform into a stunning purple gem with red undertones during dusk: the unique color-changing property of Alexandrite makes it the most valuable and expensive gemstone in the Chrysoberyl family.Â
  Diamond Specification