Blue Lapis Lazuli and blue Turquoise. The deep blue of Lapis comes from Lazurite, the light blue of Turquoise from copper. Both these gemstones were mined in mountainous regions, the Turquoise from Western Tibet, where there are a number of operating Turquoise mines, the Lapis Lazuli from the north-east corner of Afghanistan, the sole source of this gemstone for thousands of years until the early 1900s when its commercial mining began in Chile.
These two gemstones, Lapis Lazuli and Turquoise, are the only two rocks in the gemstone world, the other recognised gemstones being either organic, such as Coral, Pearl, Amber etc., or crystal, such as Ruby, Diamond, Amethyst etc.