Alexandrite in its natural form is now rarer than diamonds. It is highly desirable and sought after – not surprising considering its magical abilities. Along with pearl and moonstone, alexandrite is one of the birthstones associated with June.
Science of Colour-Change
What sets alexandrite apart from other gemstones, is its magical colour-shifting abilities. Alexandrite is a variety of chrysoberyl. Due to its unique crystal structure, it absorbs light over a very narrow range of wavelengths. In daylight, the human eye is particularly sensitive to green light and less sensitive to red light. This means that depending on the kind of light that humans view alexandrite in, the colour of the stone will appear different. When exposed to the full spectrum of light i.e., daylight, alexandrite will seem green. In contrast, under incandescent/electrical light – it will appear red. While this is the standard colour-change, it does vary between stones. Stones that display a dramatic colour change are especially rare.
History of Alexandrite
Alexandrite was first discovered in the Ural Mountains of Russia in the 1830s. Other deposits have also been found in places such as Madagascar, Tanzania, Sri Lanka, and India It was discovered by Finnish minerologist Nils Nordenskiöld. The story goes that he named it after the future Tsar – Alexander II, as it was his 16th birthday the day it was discovered. Although originally mistaken for emerald, Nordenskiöld first realised the colour-changing abilities when he viewed the stone by candlelight. At the time, the Russian military colours were red and green. As such, alexandrite was highly prized and became the official gemstone for Imperial Russia.
Because alexandrite was so popular in Russia, the mines have now been exhausted. In 1995 Russia officially stopped mining this magical stone. Mining has continued in other deposits across the globe, particularly in Brazil as a large deposit was found in 1987.