Category Archives: Science

alexandrite

could you please tell us about the gem stone alexandrite

ANSWER PERSON RESPONDS: According to Encyclopedia Britannica (http://www.lib.duke.edu/databases/descriptions/britanni.htm), “Alexandrite is a remarkable and valued variety [of chrysoberyl] that when viewed along the different crystallographic (optical) axes, changes from columbine red to orange yellow to emerald green. In addition, the stone changes from green in daylight to red in artificial light.” It also says that “The two best known and most widely used varieties of chrysoberyl are alexandrite (transparent) and Oriental cat’s-eye (opaque). Because of its great power of absorption of certain colours, alexandrite looks green in daylight and reddish purple in artificial light. The cat’s-eye is a yellowish green colour and is characterized by a luminous line. The intensity of the light in this line varies according to the brightness of the rays of light that strike it.”

The International Colored Gemstone Association website has a more expansive entry (http://gemstone.org/alex.html).