ice
To turn into or become coated with ice; freeze: The pond iced over. [1]
… the word “ice” normally means water ice, technically restricted to one of the 15 known crystalline phases of water. [2]
Called granit? in France and granita in Italy, an ice is a frozen mixture of water, sugar and liquid flavoring such as fruit juice, wine or coffee. [1]
Ice is a solid phase, usually crystalline, of a non-metallic substance that is liquid or gas at room temperature, such as ammonia ice or methane ice. [...] An unusual property of ice frozen at a pressure of one atmosphere is that the solid is some 9% less dense than liquid water. [...] As well as crystalline forms, solid water can exist in amorphous states as amorphous solid water (ASW), low-density amorphous ice (LDA), high-density amorphous ice (HDA), very high-density amorphous ice (VHDA) and hyperquenched glassy water (HGW). [2]
Wet snow, falling with temperatures very near to freezing point is converted to an icy mixture; pressure between grains induces thawing, followed by re-freezing as the water penetrates voids between grains’dry, powdery, colder snow turns to ice much less slowly because pressure is less. [...] Falling through the ice suggests the dreamer may be “skating on thin ice” and should alter course to avoid mishap. [1]
Liquid water is densest, essentially 1.00 g/cm?, at 4 ?C and becomes less dense as the water molecules begin to form the hexagonal crystals of ice as the temperature drops to 0 ?C. [...] It can appear transparent or an opaque bluish-white color, depending on the presence of impurities such as air. [...] Ice formed at high pressure has a different crystal structure and density to ordinary ice. [...] For example, the blade of an ice skate, exerting pressure on the ice, melted a thin layer, providing lubrication between the ice and the blade. [2]
Soft rime contains a high proportion of trapped air, making it appear white rather than transparent, and giving it a density about one quarter of that of pure ice. [1]
LDA forms by extremely quick cooling of liquid water (”hyperquenched glassy water”, HGW), by depositing water vapour on very cold substrates (”amorphous solid water”, ASW) or by heating high density forms of ice at ambient pressure (”LDA”). [...] The result of this is that ice floats on liquid water, which is an important factor in Earth’s climate (if ice had sunk instead of floating, any body of water would have frozen from the bottom to the surface, killing any fish and other creatures not resistant to freezing temperatures). [2]
Sources:
[1] ice: Definition from Answers.com
[2] Ice - Wikipedia, the free encyclopedia