What makes gemstones blue?
Impurities and imperfections of the gemstones color them with different shades of blue. Traces of iron within colorless beryl create one of our favorite gemstones - aquamarine. For topaz, slight gaps in the crystal structure alter how light moves through the gemstone, making it appear blue. All kinds of blue: from lightly colored Sky to intense Swiss and shady London - all colors of Blue topaz.