Kornerupine is a rare gemstone that was first discovered in Greenland in 1887. It was named after the Danish naturalist, artist and explorer Andreas Nikolaus Kornerup (1857-1883). At one time the mineral was also known as prismatine, since the crystals form in long prisms.
Kornerupine occurs in a number of colors, including white, pink, yellow, brown, green and blue. Most crystals display a strong pleochroism, usually from yellowish green to reddish brown. The emerald green and blue colors are the rarest and most valuable. Some translucent to opaque stones display chatoyancy, the cat's eye effect.
Though kornerupine was discovered in Greenland, most of the world's supply has traditionally come from Sri Lanka. The Sri Lankan gems tend to be be yellow-green or yellow-brown in color. More recently there have been new discoveries of kornerupine in Tanzania and Madagascar, in rather different colors. The African kornerupine has been found in blue and bluish-green, with a purplish pleochroism. Though the African kornerupine tend to be found in small sizes, the interesting colors have made them more popular for jewelry. Other kornerupine deposits have been found in Australia, Kenya, Burma, Canada and South Africa.