Alexandrite or Alexandrite, also known as the "Ural emerald", is a variety of chrysoberyl ore. It is a precious stone and very valuable due to its rarity.

It has the ability to change color according to light: in natural light it is usually olive green, but in incandescent light, incandescent lamps and fire, it gets a red color. Their color change and relative scarcity are due to an extremely rare combination of minerals including titanium, iron and chromium.