Chrysoberyl is a mineral composed of beryllium aluminum oxide, known for its hardness and durability. It typically appears in shades of yellow, green, or brown and is often used in jewelry. The most famous variety of chrysoberyl is alexandrite, which changes color depending on the light source. This gemstone has a hardness of 8.5 on the Mohs scale, making it one of the hardest gemstones available. Chrysoberyl is found in various locations worldwide, including Brazil, Sri Lanka, and Russia. Its unique properties and beauty make it a sought-after choice for collectors and jewelry enthusiasts alike.