#Alexandrite is one of the lesser known gemstones. It is the birthstone for June along with pearl and moonstone. It is also the gemstone of choice for the 55th anniversary present.
Alexandrite was originally discovered in Russia in 1830 and was named after Alexander II. It is known as the Chameleon of gemstones as it appears green in sunlight and red under artificial light. This is why many people say it is an emerald by day and ruby by night. There are other gemstones that change color but none as drastic as Alexandrite.
Alexandrite is the rare variety of the mineral Chrysoberyl. It is ability to color change is derived from its ability to absorb light in a narrow yellow spectrum and reflect green and red. Human eyes are more sensitive to green light so under natural light it appears green in color and under incandescent light it appears red. It is also one of the hardest gems with a 8.5 rating on the Mohrs scale.
Alexandrite is vary rare and commands a premium especially for the larger gemstones. Today it can be created in the lab and the man made version has the same physical and chemical properties.