Color and Clarity are the most important considerations when evaluating emeralds. A rich velvety green, uniform throughout the stone is the best color. Skillful cutting is important as this minimizes the prominence of flaws and can bring out the best color. Oiling with a colored fluid to improve the color is considered fraudulent treatment. Columbian stones have a secondary yellow color and the African stones have a more bluish secondary color to them. Emeralds are typically heavily flawed with cracks and inclusions of fluid and minerals. These inclusions are called "jardin" (or garden), as the inclusions resemble leaves and branches.