Chrysoberyl

Unknown Owner

A loose twinned deep green crystal grouping of chrysoberyl, this is the variety known as alexandrite. In great condition and a superb thumbnail specimen. The color changes shown at the end of the video.Alexandrite is a rare variety of the mineral chrysoberyl that is famous for its color change effect. It was first discovered in Russia in the 19th century and is valued as a gemstone. The color change is caused by trace amounts of chromium in the crystal structure, which affects how the mineral absorbs light. In daylight, which is rich in blue and green wavelengths, alexandrite appears green, while in incandescent light, which is richer in red wavelengths, it appears red to purple. This selective absorption of light produces the distinctive color change that makes alexandrite highly prized.