In gemstones, clarity refers to the amount of internal flaws (inclusions) or external flaws of each stone. Most gemstones have some amount of inclusions, and finding a flawless gemstone is rarer than finding a flawless diamond. When gemstones are formed, the process within the earth that creates them is what determines the number of flaws a cut stone will have. Some gemstones, like the emerald, are formed under violent circumstances, and, therefore, are almost always included. Darker stones-like the blue topaz, purple amethyst, and red garnet-can carry more inclusions without lessening the value because the depth of their color masks most flaws. Lighter stones will show internal inclusions much more clearly. The diamond is the most obvious example of this, although it is less common to find an internally flawless emerald than an internally flawless diamond.