Chrysoberyl is an uncommon mineral, and the color-changing variety Alexandrite is quite rare and highly valued. The nature of Alexandrite is very unique. If viewed in sunlight, its color is dark yellow-green to greenish-blue, and if viewed in incandescent light, its color changes strawberry-red to dark pink. This phenomenon is caused by the presence of certain impurities, and only occurs in Chrysoberyl from a few scattered findings.

Chrysoberyl can exhibit a floating light reflection that moves as when a polished gem is rotated. This effect is known as cymophane effect. If a Chrysoberyl exhibits a thin narrow band  of reflecting light across its length which slightly moves when a polished gem is rotated, the effect is known as a cat's eye effect. Cat's eye and cymophane effects are caused by microscopic, parallel, needlelike inclusions that cause the light to reflect distinctly within a stone. Both Cymophane and Cat's Eye are variety names used to described Chrysoberyl with these effects. Other minerals and gemstones may also exhibit cymophane or cat's eye effect, but Cymophane and Cat's Eye when used alone are only describing the Chrysoberyl type. For example, Quartz that exhibits cat's eye is known as Cat's Eye Quartz (or Quartz Cat's Eye), whereas Chrysoberyl Cat's Eye is known simply as Cat's Eye. Alexandrite may also occur in Cat's Eye or Cymophane forms, but this is extremely rare.

For additional information, see the gemstone section on Chrysoberyl, Alexandrite, and Cat's Eye.