Ice
![Frozen water in the form of an ordinary household ice cube. The white zone in the center is the result of tiny air bubbles.](/Images/godic/202502/04/Ice_cube_Air_entrapment1023.JPG")
![Snowflakes by Wilson Bentley, 1902. Snow is ice that grows from water vapor in Earth's atmosphere, which is why it usually displays crystal shapes.](/Images/godic/202502/04/SnowflakesWilsonBentley1023.jpg")
![The three-dimensional crystal structure of H2O ice Ih (c) is composed of bases of H2O ice molecules (b) located on lattice points within the two-dimensional hexagonal space lattice (a). The values for the H–O–H angle and O–H distance have come from Physics of Ice[2] with uncertainties of ±1.5° and ±0.005 Å, respectively. The black box in (c) is the unit cell defined by Bernal and Fowler.[3]](/Images/godic/202502/04/Ice_Ih_Crystal_Lattice1024.png")
![Frozen waterfall in southeast New York](/Images/godic/202502/04/Frozen_Wappinger_Creek1024.JPG")
Ice is water frozen into a solid state. Depending on the presence of impurities such as particles of soil or bubbles of air, it can appear transparent or a more or less opaque bluish-white color.
In the Solar System, ice is abundant and occurs naturally from as close to the Sun as Mercury to as far as away the Oort cloud objects. Beyond the Solar System, it occurs as interstellar ice. It is abundant on Earth's surface –particularly in the polar regions and above the snow line –and, as a common form of precipitation and deposition, plays a key role in Earth's water cycle and climate. It falls as snowflakes and hail or occurs as frost, icicles or ice spikes.