Colombia is by far the largest producer of emeralds, supplying 50-95% of the world's emeralds. Colombian emeralds are also the purest. Emerald mining and trade are, along with drug trafficking, at the center of Colombia's ongoing conflict. 1)
The Greek name for amber is 'electron'. It is from the name of amber that words such as 'electricity' are derived. Already the ancient Greeks noticed that this stone has a mysterious property - rubbed against fur, it begins to attract dust particles. 2)
Pleochroism (multicolor) is the phenomenon of color change depending on the direction of light falling on a particular crystal wall. Alexandrite is green in daylight and red in artificial lighting. This rare gemstone was named in honor of Tsar Alexander II in 1842. 3)
The name turquoise was coined in the 17th century and derives from Turkey, as the trade route for these stones from Persia led there. The ancient Romans (in pre-Turkic times) called this stone kalaite. 4)
Heliodor is a transparent yellow variety of beryl (emerald and aquamarine are also varieties of beryl). The name comes from the Greek word helios = sun (sun god) and doron = gift (“gift of the sun”); an allusion to the color of the mineral. 5)