Кристаллы льда — Photo: Ivtorov · CC BY-SA 4.0
Ice
Solid water — technically a mineral by the IMA definition, with a hexagonal crystal structure and occurrence on planets across the solar system.
Intro adapted from Wikipedia (CC BY-SA).
Ice is an IMA-recognized mineral species in the oxides & hydroxide class, with the chemical formula H₂O.
It is a member of the Amorphous, Tridymite structural group.
Key properties: Mohs hardness 1.5; specific gravity 0.9167; White streak; Vitreous luster; optically uniaxial.
IMA symbol Ice, grandfathered status — known before the IMA’s founding.
Formed at low temperatures by sublimation in the atmosphere and in layers over open bodies of water; in glacial flows and thick masses of near-continental dimensions.
It is found associated with None.
The name comes from Middle English is, iis, in turn from Old English is.