Origin

• Aquamarine is most often found in granitic pegmatites. The Free Dictionary defines granitic as "a common, coarse-grained, light-colored hard igneous rock." An igneous origin means it formed out of a melt.
  
  

Source

• The largest source of gemstone quality aquamarine currently exists in Brazil, although it has become generally recognized as the most desirable stones come from Pakistan. The United States also has a large share in the market.
  
  

Chemical Formula

• The chemical formula of aquamarine is Be3Al2Si6O18. This means it forms because of a combination of atoms of the elements beryllium (Be), aluminum (Al), silicon (Si), and oxygen (O). The presence of the silicon and oxygen makes it a silicate. It is, however, a very special variety of silicate, says the International Gem Society.
  
  

Cyclosilicate Formation

• Cyclosilicates are what the name indicates -- silicates that have become linked together to form closed rings or zeolites. According to the International Gem Society, this means the crystals contain uniformly sized spaces capable of entrapping other substances.
  
  

Gem Enhancement and Advisory

• Some aquamarines do not have the desired coloration, but are either too pale or they have a distinctly yellowish tinge. Such stones may receive a heat-treatment, which gives them the desired hue and saturation. Avoid irradiated gems, as their color is not stable.