EMERALDS are one of the four "precious" gemstones (along with diamonds, rubies, and sapphires), and are the green version of the Beryl family of gemstones (morganite, aquamarine, etc.). They have been documented as being used as far back as approximately 4000 BC in Babylon. Emeralds were worshipped by the Incas, and in prominent use throughout Ancient Egypt, by Alexander the Great, Aristotle, and the moguls of India.
DIAMONDS: known as the "stone of invincibility" (due to its hardness as a stone), diamonds are symbols of victory and the superior strength (physical, emotional, mental) of the wearer. Diamonds have also been referred to as the "king of gems", being the hardest known natural substance as well as its superior light reflective abilities.