Types of Gems by Color

Amethyst (Purple)

• Amethysts belong to the quartz family; they are the most valuable members of this family. The distinguishing factor of amethysts is their purple color. Amethysts have long been associated with royalty because purple is regarded as a royal color. Egyptian royalty favored amethysts, and fine amethysts form a part of the British Crown Jewels. Amethysts were referred to as "the stone of bishops." Amethysts also come in violet and red-violet colors. However, the deep purple colors are regarded as the most valuable.

Aquamarine (Blue)

• The name aquamarine is derived from the Latin name for seawater. This gemstone has a delicate blue to blue-green color and belongs to the beryl family. The blue color of aquamarines is due to the presence of iron, which seeps into the crystal structure from which it is formed. The most expensive aquamarines are those with a clear, transparent, blue to green blue or turquoise color. Brazil is the world's leading producer of aquamarines.

Emerald (Green)

• Emerald is a green-colored gemstone that belongs to the beryl family. The emerald is the most valuable member of this family. The emerald is considered one of the four traditional precious stones; the others are sapphires, diamonds and rubies. The green color of emeralds is due to the presence of impurities like chromium, vanadium or a mixture of the two. Columbia is the major producer of emeralds in the world.

Ruby (Red)

• Ruby is the red variety of corundum. Other colors of corundum, apart from red, are referred to as sapphire. After diamonds, corundum is the second hardest substance known to man. The name, ruby, is derived from the Latin word "rubber," which means red. Rubies are one of the more expensive precious gems. Like other gemstones, the saturation of color determines the price. Large rubies are very rare, in comparison to diamonds, and are produced in countries like Thailand, Sri Lanka, Madagascar, Myanmar and Tanzania. One world-famous ruby is the "Rosser Reeves Star Ruby," which is on display at the Smithsonian museum.