Being in an aggregate state, which tends to have a gaseous or liquid form at room temperature. The properties of ice began to be studied hundreds of years ago. About two hundred years ago, scientists discovered that water is not a simple compound, but a complex chemical element consisting of oxygen and hydrogen. After the discovery, the formula of water began to look like H 2 O.
Ice structure
H 2 O consists of two hydrogen atoms and one oxygen atom. In a quiescent state, hydrogen is located at the tops of the oxygen atom. Oxygen and hydrogen ions should occupy the vertices of an isosceles triangle: oxygen is located at the apex of a right angle. This structure of water is called a dipole.
Ice is 11.2% hydrogen and the rest is oxygen. The properties of ice depend on its chemical structure. Sometimes it contains gaseous or mechanical formations - impurities.
Ice occurs in nature in the form of a few crystalline species, which stably retain their structure at temperatures from zero and below, but at zero and above it begins to melt.
Crystal structure
The properties of ice, snow and steam are completely different and depend on. In the solid state, H 2 O is surrounded by four molecules located at the corners of the tetrahedron. Since the coordination number is low, the ice can have an openwork structure. This is reflected in the properties of the ice and its density.
Ice shapes
Ice is one of the most common substances in nature. There are the following varieties on Earth:
- river;
- lake;
- nautical;
- firn;
- glacial;
- ground.
There is ice that is directly formed by sublimation, i.e. from the vaporous state. This form takes on a skeletal shape (we call them snowflakes) and aggregates of dendritic and skeletal growth (rime, hoarfrost).
One of the most common forms is stalactites, i.e. icicles. They grow all over the world: on the surface of the Earth, in caves. This type of ice is formed by dripping water droplets at a temperature difference of about zero degrees in the autumn-spring period.
Formations in the form of ice stripes that appear at the edges of water bodies, at the border of water and air, as well as at the edge of puddles, are called ice banks.
Ice can form in porous soils in the form of fibrous veins.
Ice properties
The substance can be in different states. Based on this, the question arises: what property of ice is manifested in this or that state?
Scientists distinguish physical and mechanical properties. Each of them has its own characteristics.
Physical properties
The physical properties of ice include:
- Density. In physics, an inhomogeneous medium is represented by the limit of the ratio of the mass of the substance of the medium itself to the volume in which it is enclosed. The density of water, like that of other substances, is a function of temperature and pressure. Usually in the calculations, a constant density of water equal to 1000 kg / m 3 is used. A more accurate indicator of density is taken into account only when it is necessary to very accurately carry out calculations due to the importance of the result of the density difference.
When calculating the density of ice, it is taken into account what kind of water has become ice: as you know, the density of salt water is higher than that of distilled water. - Water temperature. Usually occurs at a temperature of zero degrees. Freezing processes occur in jumps with the release of heat. The reverse process (melting) occurs when the same amount of heat is absorbed, which was released, but without jumps, but gradually.
In nature, there are conditions under which supercooling of water occurs, but it does not freeze. Some rivers keep their water liquid even at a temperature of -2 degrees. - the amount of heat that is absorbed when the body is heated for each degree. There is a specific heat capacity, which is characterized by the amount of heat required to heat a kilogram of distilled water by one degree.
- Compressibility. Another physical property of snow and ice is compressibility, which affects the decrease in volume under the influence of increased external pressure. The reciprocal is called elasticity.
- Ice strength.
- Ice color. This property depends on the absorption of light and the scattering of rays, as well as the amount of impurities in the frozen water. River and lake ice without foreign impurities is visible in a pale blue light. Sea ice can be completely different: blue, green, blue, white, brown, and have a steel tint. Sometimes black ice can be seen. It acquires this color due to the large amount of minerals and various organic impurities.
Mechanical properties of ice
The mechanical properties of ice and water are determined by the resistance to the external environment in relation to a unit area. Mechanical properties depend on structure, salinity, temperature and porosity.
Ice is an elastic, viscous, plastic formation, but there are conditions under which it becomes hard and very brittle.
Sea ice and freshwater ice are different: the former is much more plastic and less durable.
When passing ships, the mechanical properties of ice must be taken into account. It is also important when using icy roads, ferries and more.
Water, snow and ice have similar properties that determine the characteristics of a substance. But at the same time, many other factors affect these readings: ambient temperature, impurities in the solid, as well as the initial composition of the liquid. Ice is one of the most interesting substances on Earth.
Relationships between ice crystals under different conditions of formation: 1 - prismatic ice crystal (formation occurs at a high altitude during severe frosts), 2 - tabular ice (formed during severe frosts), H - bowl-shaped ice (formed in humid caves), 4 - ordinary Snowflake. According to E.K. Lazarenko, 1971
Properties
Ice is colorless. In large clusters, it takes on a bluish tint. Glass luster. Transparent. Has no cleavage. Hardness 1.5. Fragile. Optically positive, refractive index is very low (n = 1.310, nm = 1.309).
Forms of finding
In nature, ice is a very common mineral. There are several types of ice in the earth's crust: river, lake, sea, soil, firn and glacier ice. More often it forms aggregate accumulations of fine-crystalline grains. Also known are crystalline formations of ice that arise by sublimation, that is, directly from the vaporous state. In these cases, the ice takes the form of skeletal crystals (snowflakes) and aggregates of skeletal and dendritic growth (cave ice, rime, frost and patterns on glass). Large well-cut crystals are found, but very rare. NN Stulov described ice crystals of the northeastern part of Russia, found at a depth of 55-60 m from the surface, having an isometric and columnar appearance, and the length of the largest crystal was 60 cm, and the diameter of its base was 15 cm. forms on ice crystals revealed only the faces of a hexagonal prism (1120), a hexagonal bipyramid (1121), and a pinacoid (0001).
Ice stalactites, colloquially called "icicles", are familiar to everyone. With temperature differences of about 0 ° in the autumn-winter seasons, they grow everywhere on the Earth's surface during slow freezing (crystallization) of flowing and dripping water. They are also common in ice caves.
Icy take away are strips of ice cover of ice, crystallizing at the water-air boundary along the edges of reservoirs and bordering the edges of puddles, river banks, lakes, ponds, reservoirs, etc. with non-freezing rest of the body of water. With their complete accretion, a continuous ice cover forms on the surface of the reservoir.
Ice also forms parallel-columnar aggregates in the form of fibrous veins in porous soils, and on their surface - ice antoliths.
Formation and deposits
Ice forms mainly in water basins when the air temperature drops. At the same time, an ice porridge appears on the surface of the water, composed of ice needles. From below, long ice crystals grow on it, in which the sixth-order symmetry axes are located perpendicular to the surface of the crust. The relationships between ice crystals under different conditions of formation are shown in Fig. Ice is widespread wherever there is moisture and where the temperature drops below 0 ° C. In some areas, ground ice thaws only to a shallow depth, below which permafrost begins. These are the so-called permafrost regions; in the areas of distribution of permafrost in the upper layers of the earth's crust there are so-called. underground ice, among which distinguish between modern and fossil underground ice. At least 10% of the entire land area of the Earth is covered by glaciers, the monolithic ice rock that composes them is called glacial ice... Glacial ice is formed mainly from the accumulation of snow as a result of its compaction and transformation. The ice sheet covers about 75% of Greenland and almost all of Antarctica; the greatest thickness of glaciers (4330 m.) is established near Byrd station (Antarctica). In central Greenland, the ice thickness reaches 3200 m.
Ice deposits are well known. In areas with cold, long winters and short summers, as well as in high-altitude regions, ice caves with stalactites and stalagmites are formed, among which the most interesting are Kungurskaya in the Perm region of the Urals, as well as the Dobšine cave in Slovakia.
As a result of the freezing of sea water, sea ice... The characteristic properties of sea ice are salinity and porosity, which determine the range of its density from 0.85 to 0.94 g / cm 3. Due to such a low density, ice floes rise above the water surface by 1 / 7-1 / 10 of their thickness. Sea ice begins to melt at temperatures above -2.3 ° C; it is more elastic and more difficult to break into pieces than freshwater ice.
Practical value
Ice is mainly used in refrigeration, as well as for various purposes in medicine, everyday life and technology.
Ice (eng. ICE) - H 2 O
CLASSIFICATION
| Strunz (8th Edition) | 4 / A.01-10 |
|---|---|
| Dana (8th Edition) | 4.1.2.1 |
| Hey "s CIM Ref. | 7.1.1 |
PHYSICAL PROPERTIES
| Mineral color | colorless turning into white, pale blue turning into greenish blue in thick layers |
|---|---|
| Line color | White |
| Transparency | transparent, translucent |
| Shine | glass |
| Hardness (Mohs scale) | 1.5 |
| Break | conchoidal |
| Strength | fragile |
| Density (measured) | 0.9167 g / cm3 |
| Radioactivity (GRapi) | 0 |
| Magnetic | Diamagnetic |
OPTICAL PROPERTIES
| Type of | uniaxial |
|---|---|
| Refractive indices | nα = 1.320 nβ = 1.330 |
| Maximum birefringence | δ = 1.320 |
| Optical relief | moderate |
Ushakov's Explanatory Dictionary
ICE, icy, icy, and (obsolete) ICE, icy, icy. 1.add. to the ice. Ice crust. Ice block. Ice cover. || Ice-covered, made of ice. Ice Mountain (made for skiing or the same as an iceberg). Ice ... ... Ushakov's Explanatory Dictionary
Cm … Synonym dictionary
ice- ICE, ice, decomp. icy ... Dictionary-thesaurus of synonyms for Russian speech
ice- Consisting of ice, composed of ice (eg ice sheet), or related to ice (ice regime). Syn .: ice ... Geography Dictionary
ice- glacial glacial - Topics oil and gas industry Synonyms glacial glacial EN glacial ... Technical translator's guide
App., Up. often 1. Ice is something that consists of ice formed by ice. Ice block. | Ice cover. | When they went out onto the porch, the snow, rosy from sunrise, seemed warm, and the house was overgrown with long icicles. 2. Ice ... ... Dmitriev's Explanatory Dictionary
Adj. 1. = ice, = ice ratio with noun ice associated with it 2. = icy, = icy Inherent to ice, characteristic of it. 3. transfer; = icy, = icy Indifferent, indifferent, indifferent. 4. transfer; = icy, = icy Hostile ... ... Modern explanatory dictionary of the Russian language by Efremova
Icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, icy, ... ... Word forms
Hot warm ... Dictionary of antonyms
Books
- Icy Hell, Louis Boussinard We would like to draw your attention to the book "Icy Hell" by L. Bussenard ...
- Ice cold, Katherine Laski. A silver wolf named Faolan always felt like a stranger. Doomed to death, while still a puppy, he survived, but never found a place for himself in the pack. Kindred avoid him because of ...
Ice- mineral with chem. formula H 2 O, represents water in a crystalline state.
The chemical composition of ice: H - 11.2%, O - 88.8%. Sometimes it contains gaseous and solid mechanical impurities.
In nature, ice is mainly represented by one of several crystalline modifications, stable in the temperature range from 0 to 80 ° C, with a melting point of 0 ° C. There are 10 known crystalline modifications of ice and amorphous ice. The most studied is ice of the 1st modification - the only modification found in nature. Ice occurs in nature in the form of ice itself (mainland, floating, underground, etc.), as well as in the form of snow, frost, etc.
See also:
STRUCTURE
The crystal structure of ice is similar to the structure: each H2O molecule is surrounded by four molecules closest to it, located at equal distances from it, equal to 2.76Α and located at the vertices of a regular tetrahedron. Due to the low coordination number, the ice structure is openwork, which affects its density (0.917). Ice has a hexagonal lattice and is formed by freezing water at 0 ° C and atmospheric pressure. The lattice of all crystalline modifications of ice has a tetrahedral structure. Unit cell parameters of ice (at t 0 ° C): a = 0.45446 nm, c = 0.73670 nm (c is the doubled distance between adjacent main planes). With decreasing temperature, they change very insignificantly. The Н 2 0 molecules in the ice lattice are linked by hydrogen bonds. The mobility of hydrogen atoms in the ice lattice is much higher than the mobility of oxygen atoms, due to which the molecules change their neighbors. In the presence of significant vibrational and rotational motions of molecules in the ice lattice, translational dismounts of molecules from the site of their spatial connection appear with disruption of further ordering and the formation of dislocations. This explains the manifestation of specific rheological properties in ice, which characterize the relationship between irreversible deformations (flow) of ice and the stresses that caused them (plasticity, viscosity, yield stress, creep, etc.). Due to these circumstances, glaciers flow similarly to highly viscous fluids, and, thus, natural ice actively participates in the water cycle on Earth. Ice crystals are relatively large (transverse size from fractions of a millimeter to several tens of centimeters). They are characterized by the anisotropy of the viscosity coefficient, the value of which can vary by several orders of magnitude. Crystals are capable of reorientation under the action of loads, which affects their metamorphization and the speed of glacier flow.
PROPERTIES
Ice is colorless. In large clusters, it takes on a bluish tint. Glass luster. Transparent. Has no cleavage. Hardness 1.5. Fragile. Optically positive, refractive index is very low (n = 1.310, nm = 1.309). 14 types of ice are known in nature. True, everything, except for the usual ice, crystallizing in the hexagonal system and designated as ice I, is formed under exotic conditions - at very low temperatures (about -110 150 0С) and high pressures, when the angles of hydrogen bonds in the water molecule change and systems are formed, other than hexagonal. Such conditions resemble space conditions and are not found on Earth. For example, at temperatures below –110 ° C, water vapor falls out on a metal plate in the form of octahedrons and cubes several nanometers in size - this is the so-called cubic ice. If the temperature is slightly above –110 ° C, and the vapor concentration is very low, a layer of extremely dense amorphous ice forms on the plate.
MORPHOLOGY
In nature, ice is a very common mineral. There are several types of ice in the earth's crust: river, lake, sea, soil, firn and glacier ice. More often it forms aggregate accumulations of fine-crystalline grains. Also known are crystalline formations of ice that arise by sublimation, that is, directly from the vaporous state. In these cases, the ice takes the form of skeletal crystals (snowflakes) and aggregates of skeletal and dendritic growth (cave ice, rime, frost and patterns on glass). Large well-cut crystals are found, but very rare. NN Stulov described ice crystals of the northeastern part of Russia, found at a depth of 55-60 m from the surface, having an isometric and columnar appearance, and the length of the largest crystal was 60 cm, and the diameter of its base was 15 cm. forms on ice crystals revealed only the faces of a hexagonal prism (1120), a hexagonal bipyramid (1121) and a pinacoid (0001).
Ice stalactites, colloquially called "icicles", are familiar to everyone. With temperature differences of about 0 ° in the autumn-winter seasons, they grow everywhere on the Earth's surface during slow freezing (crystallization) of flowing and dripping water. They are also common in ice caves.
Ice banks are strips of ice cover of ice crystallizing at the water-air boundary along the edges of reservoirs and bordering the edges of puddles, river banks, lakes, ponds, reservoirs, etc. with non-freezing rest of the body of water. With their complete accretion, a continuous ice cover forms on the surface of the reservoir.
Ice also forms parallel-columnar aggregates in the form of fibrous veins in porous soils, and ice antolites on their surface.
ORIGIN
Ice forms mainly in water basins when the air temperature drops. At the same time, an ice porridge appears on the surface of the water, composed of ice needles. From below, long ice crystals grow on it, in which the sixth-order symmetry axes are located perpendicular to the surface of the crust. The relationships between ice crystals under different conditions of formation are shown in Fig. Ice is widespread wherever there is moisture and where the temperature drops below 0 ° C. In some areas, ground ice thaws only to a shallow depth, below which permafrost begins. These are the so-called permafrost regions; In the areas of permafrost distribution in the upper layers of the earth's crust, there are so-called underground ice, among which modern and fossil underground ice are distinguished. At least 10% of the entire land area of the Earth is covered with glaciers, the monolithic ice rock that composes them is called glacial ice. Glacial ice is formed mainly from the accumulation of snow as a result of its compaction and transformation. The ice sheet covers about 75% of Greenland and almost all of Antarctica; the greatest thickness of glaciers (4330 m.) is established near Byrd station (Antarctica). In central Greenland, the ice thickness reaches 3200 m.
Ice deposits are well known. In areas with cold, long winters and short summers, as well as in high-altitude regions, ice caves with stalactites and stalagmites are formed, among which the most interesting are Kungurskaya in the Perm region of the Urals, as well as the Dobšine cave in Slovakia.
As a result of the freezing of sea water, sea ice is formed. The characteristic properties of sea ice are salinity and porosity, which determine the range of its density from 0.85 to 0.94 g / cm 3. Due to such a low density, ice floes rise above the water surface by 1 / 7-1 / 10 of their thickness. Sea ice begins to melt at temperatures above -2.3 ° C; it is more elastic and more difficult to break into pieces than freshwater ice.
APPLICATION
In the late 1980s, the Argonne laboratory developed a technology for the manufacture of ice slurry (Ice Slurry), capable of flowing freely through pipes of various diameters, without collecting in ice build-up, without sticking or clogging the cooling system. The salty water suspension consisted of many very small round-shaped ice crystals. Due to this, the mobility of water is preserved and, at the same time, from the point of view of heating technology, it is ice, which is 5-7 times more efficient than plain cold water in cooling systems of buildings. In addition, such mixtures are promising for medicine. Experiments on animals have shown that microcrystals of the ice mixture perfectly pass into rather small blood vessels and do not damage cells. Frozen Blood lengthens the time during which the victim can be saved. For example, in case of cardiac arrest, this time is lengthened, according to conservative estimates, from 10-15 to 30-45 minutes.
The use of ice as a structural material is widespread in the circumpolar regions for the construction of dwellings - igloo. Ice is part of the Pikerite material proposed by D. Pike, from which it was proposed to make the world's largest aircraft carrier.
Ice (English Ice) - H 2 O
CLASSIFICATION
| Strunz (8th Edition) | 4 / A.01-10 |
| Nickel-Strunz (10th Edition) | 4.AA.05 |
| Dana (8th Edition) | 4.1.2.1 |
| Hey's CIM Ref. | 7.1.1 |
Ice supplies the planet with a huge amount of fresh water and keeps the global water level in the world's oceans from catastrophic rise.
In addition, ice contains useful information about the past of our planet, and also tells about the future of the climate on Earth.
Here are the most interesting facts about ice on Earth and beyond:
Ice names
1. Ice has many different names.
Only sea ice has several names, not to mention ice in the Arctic and Antarctic. Fine ice, in-water ice, nilas, and pancake ice are just some of what can be found in the Arctic and Antarctica.
If you swim near the North or South Pole, then you better know where the iceberg is, and where is the bottom of the fast ice (ice bonded to the shore or bottom), what is the difference between the breech and hummock, and between a floating ice floe and a flauberg (floating mountain) ...
But if you think that these words are more than enough for you, then you will be surprised to learn that the people of Alaska, the Inupiat, have 100 different names for ice, which is logical for the people who live in cold places.
Freezing rain
2. Freezing rain occurs when snow passes through the warm and cold layers of the atmosphere.
Freezing rain can be deadly. This is how it occurs: snow enters the warm layer of the atmosphere and melts, turning into raindrops, then passes through the cold layer of air. Raindrops do not have time to freeze, passing this cold layer, but when they collide with a cold surface, these drops instantly turn into ice.
As a result, a thick layer of ice forms on the roads, and everything around turns into an ice rink. Ice also builds up on electrical wires, which can lead to breakage. The ice accumulated on the branches can break them off, which is very dangerous for people.
Today there are laboratories in which scientists are trying to predict where and how this rain might strike. One of these laboratories is located in New Hampshire, where scientists create simulations of freezing rain.
Dry ice
3. Dry ice does not consist of water.
In fact, it is frozen carbon dioxide, which can change its state from solid to gaseous at room temperature and atmospheric pressure, bypassing the liquid phase. Dry ice is quite useful for keeping some items cold, as it freezes at 78.5 degrees Celsius.
The invention of the refrigerator
4. Ice helped people invent the refrigerator.
Thousands of years ago, people already used ice to keep food fresh. In the 1800s, people carved ice cubes from frozen lakes, brought them in and stored them in special isolated rooms and cellars. Towards the end of the 19th century, people were using household ice boxes for food, which later turned into refrigerators.
Ice not only made life easier for individual homes, but also played a key role in the mass production and distribution of meat and other perishable foods. This all eventually led to urbanization and the development of many other industries.
By the end of the century, pollution and mountains of debris dumped into sewage were contaminating many of the world's natural ice reserves. This problem led to the development of the modern electric refrigerator. The very first commercially successful refrigerator was released in 1927 in the United States.
Greenland ice sheet
5. The Greenland ice sheet contains 10% of the world's glacial ice on the planet, and it is melting rapidly.
This ice sheet is the second largest ice mass in the world after the Antarctic ice sheet, and contains enough water to raise the world sea level by at least 6 meters. If every glacier and ice sheet melts on Earth, the water level will rise by more than 80 meters.
Greenland's ice sheet is losing 8,000 tons every second, according to a study published in 2016 in the journal Nature Climate Change. Scientists have been researching this ice sheet for several years now to better understand how it is responding to climate change on Earth.
Icebergs and glaciers
6. Icebergs and glaciers are not only white.
White light is made up of many colors, and each has a different wavelength. As the snow builds up on the iceberg, the air bubbles in the snow contract and more light enters the ice than is reflected from the bubbles and small ice crystals.
This is where the trick comes in: colors with longer wavelengths, such as red and yellow, are absorbed by ice, while colors with shorter wavelengths, such as blue and green, reflect light. Therefore, icebergs and glaciers have a bluish-greenish tint.
Ice ages on Earth
7. There have been many ice ages on Earth.
Often when we hear about an ice age, we imagine only one such period. In fact, even before us, there were several ice ages on the planet, and they were all very severe. Scientists assume that at some time period our planet was completely frozen, and scientists call this hypothesis "Earth-snowball".
There are suggestions that some ice ages were the result of the evolution of new life forms - plants, as well as unicellular and multicellular organisms - that contributed to the change in the concentration of oxygen and carbon dioxide in the atmosphere so much that it led to a change in the greenhouse effect.
The earth will continue to go through cycles of warm and cold spells. However, at this stage, scientists predict that over the next 100 years, the rate of warming will be at least 20 times higher than the rate of previous periods of warming.
Fresh water on earth
8. More than 2/3 of the Earth's fresh water reserves are stored in glaciers.
Melting glaciers will not only lead to an increase in the level of the world ocean, but will also lead to a significant decrease in the level of fresh water reserves and its quality. In addition, the melting of glaciers will lead to a problem of energy supply, as many hydroelectric power plants will not be able to work properly - due to melting, many rivers will change their channels. In some regions, such as South America and the Himalayas, these problems are already being felt.
Ice planets
9. Ice is not only on Earth.
Water is composed of hydrogen and oxygen, and these elements are abundant in our solar system. Depending on their proximity to the Sun, different planets in our solar system have different volumes of water. For example, Jupiter and Saturn are far from the Sun, and their moons have much more water than Earth, Mars and Mercury, where high temperatures make it more difficult for hydrogen and oxygen to create water molecules.
Europa is a satellite of Jupiter
The distant planets have several frozen satellites, one of which is called Europa - the 6th satellite of Jupiter. This satellite is covered with several layers of ice, the total thickness of which is several kilometers. On the surface of Europa, cracks and undulations were discovered, which were probably formed by waves of the underwater ocean.
Enceladus - Moon of saturn
The large reserves of water on the Europa satellite have allowed scientists to assume that there may be life on it.
Ice volcanoes (cryovolcanoes)
10. There is such a thing as an ice volcano (cryovolcano)
Enceladus, one of the moons of Saturn, boasts one very interesting feature. Its north pole area contains cryovolcanoes, an exotic type of geyser that spew ice instead of lava.
This happens when ice deep below the surface heats up and turns into steam, after which it erupts into the cold atmosphere of the satellite in the form of ice particles.
Life on Mars
11. Ice on Mars can help you learn about life on the Red Planet.
According to information from satellites, there is ice on Mars (both dry and frozen water). This ice is found in the polar caps of the Red Planet and in permafrost regions.
Mars' ice reserves may provide an answer to a question that has been debated for many years - can life be sustained on Mars.
In future missions to Mars, scientists will try to find out if the reserves of water that may emerge from underground glaciers can contain life.
Frozen human mummy
12. The best preserved mummies were frozen.
La Donzella
From the Andes to the Alps, frozen human remains allow scientists to learn more and more about how people lived hundreds and thousands of years ago. Some of the best-preserved remains belong to a 15-year-old Inca teenager named La Doncella or Virgo.
Presumably, the girl was sacrificed about 500 years ago, on the summit of the Llullaillaco volcano, which is located in Argentina. The girl was found with other children. She is believed to have died of hypothermia.
Ötzi
Another frozen mummy - Oetzi - belongs to the Chalcolithic era. This ice mummy of a man was found in 1991 in the Ötztal Alps near the Austrian-Italian border. Presumably the mummies are 5,300 years old.
