Aquamarine is the traditional birthstone for the month of March.
Aquamarine means seawater. It’s the perfect name, since the stone ranges from pale green to middle blues. The shade depends on the how much of different forms of iron impurities the stone has. (A different iron produces yellow and a combination makes a dark blue!)
Compared to emerald, it’s a relatively common form of beryl-it’s found all over the world, but most gem quality stones come from Brazil.
Pale aquamarines can be confused with many other types of gems.
In the 1740s a huge diamond was mined in Brazil. It became the property of the Portuguese royal family-the Braganzas. This Braganza Diamond vanished. Some believe it was cut into much smaller gems and set in the crown jewels. In this case the famous diamond might have been a particularly brilliant aquamarine or white topaz. (Apparently the reports can’t even agree on what color the diamond was-famous, but poorly reported!)
There’s a beautiful carved aquamarine, also of Brazilian origin, just recently acquired by the Smithsonian Museum of Natural History. It’s known as the Dom Pedro and is 14″ long and almost 5 lbs.