Water ice (from other Greek. Λίθος - stone [1] ) is one of the most common minerals on Earth . In mineralogy, the Ice Group is included in the class of Simple and Complex Oxides , but stands out for its unique properties [2] .
| Ice (ice group) | |
|---|---|
 Ice crystals (snow, hoarfrost, etc.) | |
| Formula | H 2 O |
| Impurity | Gaseous and solid solids |
| Physical properties | |
| Color | Colorless, bluish, white |
| Trait color | White |
| Shine | Glass |
| Transparency | Transparent |
| Hardness | 1,5 |
| Cleavage | Does not possess |
| Kink | Crayfish |
| Density | 0.9167 g / cm³ |
| Syngonia | Hexagonal |
| Refractive index | nω 1.309, nε 1.311 |
Content
- 1 Crystal structure and properties
- 1.1 Morphology
- 1.2 Syngonia
- 1.3 Optical properties
- 2 Water and ice in mineralogy
- 3 varieties of ice
- 4 Ice in space
- 5 See also
- 6 notes
- 7 References
Crystal structure and properties
Ice has a molecular crystalline structure that is locally close to the structure of diamond (each H 2 O molecule has a coordination number of 4). According to the general arrangement of molecules, the ice structure is similar to the structure of wurtzite , but disordered by hydrogen atoms.
Morphology
Usually, snow crystals ( Snowflake or hoarfrost ) have a complex 6-ray stellar growth figure of various shapes with hexagonal symmetry ( Hexagonal syngony ).
On frosty days, Ice needles fall out. Dendrites and patterned ice formations are widely known. In ice caves, ice crystals are found in the form of regular hexagonal plates, tabular individuals and complex splices. Ice crystals of unique size and good faceting are known (up to 40 cm in length and up to 15 cm in diameter), found in northeast Asia in mine workings under permafrost conditions.
Syngonia
- hexagonal; dihexagonal pyramidal (L 6 6P), (P6 3 mc (С 4 6v ). а 0 = 7.82; с 0 = 7.36 [3] ..
According to the international classification [4] :
- Class: hexagonal syngony 6 / mmm (6 / m 2 / m 2 / m) - dihexagonal dipyramidal
- Space Group: P6 3 / mmc
- Cell parameters: a = 0.4498 nm, c = 0.7338 nm. The ratio a: c = 1: 1.631, V = 128.57 ų, Z = 4.
Optical Properties
- Type: Uniaxial
- RI values: n ω = 1,309, n ε = 1,311
- Maximum birefringence: δ = 0.001
Mineralogy Water and Ice
The static ideas of K. Linney’s nature system assigned little importance to the study of water in mineralogy . Water was considered as an object of study of geography [5] .
Water is of exceptional importance not only in chemistry , physics (see ice ) but also in mineralogy . Water takes part in the genesis of many minerals . It often plays a decisive role and helps explain the origin of most minerals. This confirms that natural waters themselves are among the minerals.
In 1931, V.I. Vernadsky paid particular attention to the study of water as a mineral . He isolated oxygen compounds with hydrogen in [6] :
- Natural water group.
- Hydrogen peroxide .
Water as a geological phenomenon has existed on Earth for several billion years and has more than 1000 varieties (V. I. Vernadsky described about 540 of them) [7] .
Ice Varieties
Depending on the conditions (temperature, pressure, specific volume), ice can be in several modifications [8] :
- Ice I is ordinary water ice found on planet Earth .
- Ice II - ice is maintained at normal pressure, at a temperature below −170 ° C.
- Ice III - ice is maintained at ordinary pressure, at a temperature below −170 ° C.
- Ice IV - unstable phase
- Ice V - ice is maintained at ordinary pressure, at a temperature below −170 ° C.
- Ice VI is the stable phase of frozen heavy water .
- Ice VII - ice formed at very high pressures (> 20 GPa).
- Ice VIII is an ordered form of ice-VII.
- Ice IX is the unstable phase of supercooled ice-III.
- and others
Amorphous ice occurs during the condensation of water vapor on a surface cooled to −160 ° С, exists at temperatures below −130 ° С.
Ice in space
Ice is widespread in the universe, huge masses of ice are on different planets.
Water ice in the interstellar space can take various crystalline and amorphous forms depending on temperature and pressure. Crystallization of initially amorphous ice occurs at temperatures of about 90 K (or −183 ° C). This phase change is irreversible. Interstellar ice, at temperatures below 90 K, is mainly in the dense amorphous phase [9] .
See also
- Water , Ice , Snow , Snowflake , Hoarfrost , Ice Needles
- Oxides
- Hydrochemistry
Notes
- ↑ Fasmer M. Ice // Etymological Dictionary of the Russian Language. T. 2. M.: Astrel. AST, 2009.S. 474.
- ↑ Betekhtin A.G. Simple and complex oxides // Mineralogy course. M .: CD University, 2014.S. 297-368
- ↑ Betekhtin A.G. Ice group // Mineralogy course. M .: CD University, 2014. S. 298-301
- ↑ Hellmann G. Schneekrystalle (unreachable link) . Berlin: Verlag von Rudolf Mückenberger, 1893.66 p.
- ↑ Vernadsky V.I. Natural water in mineralogy // History of natural waters. Collected works. T. 5. M .: Nauka, 2013.S. 26–28.
- ↑ V.I. Vernadsky. History of Minerals: Hydrogenic Minerals // Collected Works. T. 5. M.: Nauka, 2013.S. 15-18.
- ↑ Vernadsky V.I. Conclusion // History of natural waters. Collected works. T. 5. M.: Nauka, 2013. S. 515-516.
- ↑ Kotlyakov V. M. Ordinary mineral with extraordinary properties // World of snow and ice. Moscow: Nauka, 1994.S. 7-15.
- ↑ Jenniskens P., Blake D. Science. 1994.265, 5173, P. 753. cit. by EF van Dishoeck, EA Bergin, DC Lis, JI Lunine Water: from clouds to planets . 2014.
Links
- Vibe D.Z. Everything that you wanted to know about water, but were embarrassed to ask . Review 2015
- Ice on Mindat. (eng.)