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. Diamonds have also been know as a strong symbol of invincibility in the wearer.
AMETHYST is said to be a calming stone (great for aiding meditation); and in folklore is also know as the "Sobriety Stone". It also supposedly protects travelers and aids in overcoming personal loss.