Ice is water frozen into a solid state. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions. The addition of other materials such as soil may further alter its appearance. Ice appears naturally in forms of snowflakes, hail, icicles, ice spikes and candles, glaciers, pack ice, frost, and polar ice caps. It is an important component of the global climate and plays an important role in the water cycle.