Alexandrite is a rare and valuable gemstone known for its unique color-changing properties. It appears green in daylight and shifts to a reddish-purple hue under incandescent light. This phenomenon is due to the way the stone absorbs and reflects light, making it highly sought after in the jewelry market. Discovered in the Ural Mountains of Russia in the 1830s, Alexandrite is named after Tsar Alexander II. The gemstone is a variety of chrysoberyl and is prized for its beauty and rarity. High-quality stones can be quite expensive, often exceeding the price of diamonds.