Alexandrite is one of the rarest and most valuable gemstones. It was discovered by chance during a search for emeralds near Yekaterinburg in 1833, on the day of Alexander the Second's birthday anniversary (hence the name).^[1] It is a very valuable variety of chrysoberyl, which ranks as the third-hardest gemstone, right after diamond and corundum.

Alexandrite changes its color depending upon the nature of ambient lighting. It is emerald-colored or grass-green in daylight and purple-reddish in artifical light. Its color varies also from red to orange-yellowish depending on the angle from which it is looked at.