Alexandrite is one of the rarest and most expensive gems on the planet. The price for alexandrite can be as little as $100.00 a carat or as much as $100,000.00+ per carat. The price depends on color, color-change (this gem must change color in different lighting sources and the greater the color change and more beautiful the colors can raise the value dramatically,) and the stone must have excellent cut, polish and clarity. It is also available in a cat's eye form but the line should be razor sharp and have a good color change for it to have any value. The cats eye form will appear almost black in normal light. Beware of sillimanite and other gems being sold as Cat's Eye Alexandrite. Check for color change!