DIAMONDS are the toughest gem in the world, and can be found in 6 of the 7 continents across the world (sorry Antartica). Many times referred to as the "King of Gems", diamonds symbolize light as when its colorless facets catch the sun, they display the entire color spectrum.
AQUAMARINE is the blue version of Beryl (also containing Morganite, Emeralds, etc.). It was believed to be the treasure of mermaids as well as symbolic of eternal youth and happiness. It was used as good luck talismans for travelers and sailors.