A stalagmite is a type of rock formation that rises from the floor of a cave due to the accumulation of material deposited on the floor from ceiling drippings. Stalagmites may be composed of lava, mud, pitch, sand and amberat; the corresponding formation hanging down from the ceiling of a cave is a stalactite. Mnemonics have been developed for; the most common stalagmites are speleothems, which form in limestone caves. Stalagmite formation occurs only under certain pH conditions within the cavern, they form through deposition of calcium carbonate and other minerals, precipitated from mineralized water solutions. Limestone is the chief form of calcium carbonate rock, dissolved by water that contains carbon dioxide, forming a calcium bicarbonate solution in caverns; the partial pressure of carbon dioxide in the water must be greater than the partial pressure of carbon dioxide in the cave chamber for conventional stalagmite growth. If stalactites – the ceiling formations – grow long enough to connect with stalagmites on the floor, they form a column.
Stalagmites should not be touched, since the rock buildup is formed by minerals precipitating out of the water solution onto the existing surface. Oils and dirt from human contact can stain the formation and change its color permanently. Another type of stalagmite is formed in lava tubes; the mechanism of formation is similar to that of limestone stalagmites. It is still the deposition of material on the floors of caves. A key difference with lava stalagmites is that once the lava has ceased flowing, so too will the stalagmites cease to grow; this means. Stalagmites in lava tubes are rarer than their stalactite counterparts because during formation the dripping material falls onto still-moving lava floors that absorb or carry the material away; the generic term "lavacicle" has been applied to lava stalactites and stalagmites indiscriminately, evolved from the word "icicle". A common stalagmite found seasonally or year round in many caves is the ice stalagmite referred to as icicles in above-ground contexts.
Water seepage from the surface will penetrate into a cave and if temperatures are below freezing temperature, the water will collect on the floor into stalagmites. Deposition may occur directly from the freezing of water vapor. Similar to lava stalagmites, ice stalagmites form quickly within hours or days. Unlike lava stalagmites however, they may grow back as long. Ice stalagmites are more common than their stalactite counterparts because warmer air rises to the ceilings of caves and may raise temperatures to above freezing. Ice stalactites may form corresponding stalagmites below them, given time, may grow together to form an ice column. Stalactites and stalagmites can form on concrete ceilings and floors, although they form much more there than in the natural cave environment; the secondary deposits derived from concrete are the result of concrete degradation, where calcium ions are leached out of the concrete in solution and redeposited on the underside of a concrete structure to form stalactites and stalagmites.
Calcium carbonate deposition as a stalagmite occurs when the solution carries the calcium laden leachate solution to the ground under the concrete structure. Carbon dioxide is absorbed into the alkaline leachate solution, which facilitates the chemical reactions to deposit calcium carbonate as a stalagmite; these stalagmites grow taller than a few centimetres. Secondary deposits, which create stalagmites, flowstone etc. outside the natural cave environment, are referred to as “calthemites”. These concrete derived secondary deposits can’t be referred to as “speleothems” due to the definition of the word; the largest known stalagmite in the world exceeds 70 metres in height and is in Sơn Đoòng Cave, Vietnam. In the Zagros Mountains of south Iran 6 km from the ancient city of Bishapur, in the Shapur cave on the fourth of five terraces stands the 3rd-century colossal statue of Shapur I, second ruler of the Sassanid Empire; the statue, carved from one stalagmite, is nearly 7 m high. The Virtual Cave: Stalagmites
In chemistry, a salt is an ionic compound that can be formed by the neutralization reaction of an acid and a base. Salts are composed of related numbers of cations and anions so that the product is electrically neutral; these component ions can be inorganic, such as organic, such as acetate. Salts can be classified in a variety of ways. Salts that produce hydroxide ions when dissolved in water are called alkali salts. Salts that produce acidic solutions are acidic salts. Neutral salts are those salts that are neither basic. Zwitterions contain an anionic and a cationic centres in the same molecule, but are not considered to be salts. Examples of zwitterions include amino acids, many metabolites and proteins. Solid salts tend to be transparent. In many cases, the apparent opacity or transparency are only related to the difference in size of the individual monocrystals. Since light reflects from the grain boundaries, larger crystals tend to be transparent, while the polycrystalline aggregates look like white powders.
Salts exist in many different colors, which arise either from the cations. For example: sodium chromate is yellow by virtue of the chromate ion potassium dichromate is orange by virtue of the dichromate ion cobalt nitrate is red owing to the chromophore of hydrated cobalt. copper sulfate is blue because of the copper chromophore potassium permanganate has the violet color of permanganate anion. Nickel chloride is green of sodium chloride, magnesium sulfate heptahydrate are colorless or white because the constituent cations and anions do not absorb in the visible part of the spectrumFew minerals are salts because they would be solubilized by water. Inorganic pigments tend not to be salts, because insolubility is required for fastness; some organic dyes are salts, but they are insoluble in water. Different salts can elicit all five basic tastes, e.g. salty, sour and umami or savory. Salts of strong acids and strong bases are non-volatile and odorless, whereas salts of either weak acids or weak bases may smell like the conjugate acid or the conjugate base of the component ions.
That slow, partial decomposition is accelerated by the presence of water, since hydrolysis is the other half of the reversible reaction equation of formation of weak salts. Many ionic compounds exhibit significant solubility in water or other polar solvents. Unlike molecular compounds, salts dissociate in solution into cationic components; the lattice energy, the cohesive forces between these ions within a solid, determines the solubility. The solubility is dependent on how well each ion interacts with the solvent, so certain patterns become apparent. For example, salts of sodium and ammonium are soluble in water. Notable exceptions include potassium cobaltinitrite. Most nitrates and many sulfates are water-soluble. Exceptions include barium sulfate, calcium sulfate, lead sulfate, where the 2+/2− pairing leads to high lattice energies. For similar reasons, most alkali metal carbonates are not soluble in water; some soluble carbonate salts are: potassium carbonate and ammonium carbonate. Salts are characteristically insulators.
Molten salts or solutions of salts conduct electricity. For this reason, liquified salts and solutions containing dissolved salts are called electrolytes. Salts characteristically have high melting points. For example, sodium chloride melts at 801 °C; some salts with low lattice energies are liquid near room temperature. These include molten salts, which are mixtures of salts, ionic liquids, which contain organic cations; these liquids exhibit unusual properties as solvents. The name of a salt starts with the name of the cation followed by the name of the anion. Salts are referred to only by the name of the cation or by the name of the anion. Common salt-forming cations include: Ammonium NH+4 Calcium Ca2+ Iron Fe2+ and Fe3+ Magnesium Mg2+ Potassium K+ Pyridinium C5H5NH+ Quaternary ammonium NR+4, R being an alkyl group or an aryl group Sodium Na+ Copper Cu2+Common salt-forming anions include: Acetate CH3COO− Carbonate CO2−3 Chloride Cl− Citrate HOC2 Cyanide C≡N− Fluoride F− Nitrate NO−3 Nitrite NO−2 Oxide O2− Phosphate PO3−4 Sulfate SO2−4 Salts with varying number of hydrogen atoms, with respect to the parent acid, replaced by cations can be referred to as monobasic, dibasic or tribasic salts: Sodium phosphate monobasic Sodium phosphate dibasic Sodium phosphate tribasic Salts are formed by a chemical reaction between: A base and an acid, e.g. NH3 + HCl → NH4Cl A metal and an acid, e.g. Mg + H2SO4 → MgSO4 + H2 A metal and a non-metal, e.g. Ca + Cl2 → CaCl2 A base and an a
Travertine is a form of limestone deposited by mineral springs hot springs. Travertine has a fibrous or concentric appearance and exists in white, cream-colored, rusty varieties, it is formed by a process of rapid precipitation of calcium carbonate at the mouth of a hot spring or in a limestone cave. In the latter, it can form stalactites and other speleothems, it is used in Italy and elsewhere as a building material. Travertine is a terrestrial sedimentary rock, formed by the precipitation of carbonate minerals from solution in ground and surface waters, and/or geothermally heated hot-springs. Similar deposits formed from ambient-temperature water are known as tufa; the word'travertine' is derived from the Italian travertino, itself a derivation of the Latin tiburtinus'of Tibur'. Its namesake is the origin of Tivoli, a district near Rome. Modern travertine is formed from geothermally heated supersaturated alkaline waters, with raised pCO2. On emergence, waters degas CO2 due to the lower atmospheric pCO2, resulting in an increase in pH.
Since carbonate solubility decreases with increased pH, precipitation is induced. Precipitation may be enhanced by factors leading to a reduction in pCO2, for example increased air-water interactions at waterfalls may be important, as may photosynthesis. Precipitation may be enhanced by evaporation in some springs. Both calcite and aragonite are found in hot spring travertines; when pure and fine, travertine is white, but it is brown to yellow due to impurities. Travertine may precipitate out directly onto rock and other inert materials as in Pamukkale or Mammoth Hot Springs for example. In Italy, well-known travertine quarries exist in Tivoli and Guidonia Montecelio, where the most important quarries since Ancient Roman times can be found; the Guidonia quarry has major historic value, as it was one of the quarries where Gian Lorenzo Bernini selected material from which to build the famous Colonnade of St. Peter's Square in Rome in 1656-1667. Michaelangelo chose travertine as the material for the external ribs of the dome of St Peter's Basilica.
Travertine derives its name from the former town, known as Tibur in ancient Roman times. The ancient name for the stone was lapis tiburtinus, meaning tibur stone, corrupted to travertino. Detailed studies of the Tivoli and Guidonia travertine deposits revealed diurnal and annual rhythmic banding and laminae, which have potential use in geochronology. Cascades of natural lakes formed behind travertine dams can be seen in Pamukkale, a UNESCO World Heritage Site. Other places with such cascades include Huanglong in Sichuan Province of China, the Mammoth Hot Springs in the US, Egerszalók in Hungary, Abbass Abad, Atash Kooh, Badab-e Surt in Iran, Band-i-Amir in Afghanistan, Lagunas de Ruidera, Hierve el Agua, Oaxaca and Semuc Champey, Guatemala. In Central Europe's last post-glacial palaeoclimatic optimum, huge deposits of tufa formed from karst springs. Important geotopes are found at the Swabian Alb in valleys at the foremost northwest ridge of the cuesta. On a smaller scale, these karst processes are still working.
Travertine has been an important building material since the Middle Ages. Travertine has formed sixteen huge, natural dams in a valley in Croatia known as Plitvice Lakes National Park. Clinging to moss and rocks in the water, the travertine has built up over several millennia to form waterfalls up to 70 m in height. In the U. S. the most well-known place for travertine formation is Yellowstone National Park, where the geothermal areas are rich in travertine deposits. Wyoming has travertines in Hot Springs State Park in Thermopolis. Oklahoma has two parks dedicated to this natural wonder. Turner Falls, the tallest waterfall in Oklahoma, is a 77 feet cascade of spring water flowing over a travertine cave. Honey Creek creates miles of travertine shelves both up and downstream. Many small waterfalls upstream in the dense woods repeat the travertine-formation effect; the city of Davis has made it a tourist attraction. Another travertine resource is in Oklahoma, 10 miles east of Turner Falls. Travertine Creek flows through a spring-water nature preserve within the boundaries of the Chickasaw National Recreation Area.
In Texas, the city of Austin and its surrounding "Hill Country" to the south is built on limestone. The area has many travertine formations, such as those found at Gorman Falls within Colorado Bend State Park, the nature preserve known as Hamilton Pool, the West Cave Preserve, Krause Springs in Spicewood. Hanging Lake in Glenwood Canyon in Colorado has aqua blue water. Rifle Falls State Park in Colorado features a triple waterfall over a travertine dam. In Arizona, on the south side of the Grand Canyon there is the Havasupai Reservation. Flowing through it is Havasu Creek, which has extensive travertine deposits. Three major waterfalls, Navajo Falls, Havasu Falls, Mooney Falls, are all located downstream from the town of Supai. There are numerous smaller cataracts formed by travertine dams; these features are located about 2 miles from Supai Village, are accessible by foot or horseback. In Iceland, the Hva
A mineral is, broadly speaking, a solid chemical compound that occurs in pure form. A rock may consist of a single mineral, or may be an aggregate of two or more different minerals, spacially segregated into distinct phases. Compounds that occur only in living beings are excluded, but some minerals are biogenic and/or are organic compounds in the sense of chemistry. Moreover, living beings synthesize inorganic minerals that occur in rocks. In geology and mineralogy, the term "mineral" is reserved for mineral species: crystalline compounds with a well-defined chemical composition and a specific crystal structure. Minerals without a definite crystalline structure, such as opal or obsidian, are more properly called mineraloids. If a chemical compound may occur with different crystal structures, each structure is considered different mineral species. Thus, for example and stishovite are two different minerals consisting of the same compound, silicon dioxide; the International Mineralogical Association is the world's premier standard body for the definition and nomenclature of mineral species.
As of November 2018, the IMA recognizes 5,413 official mineral species. Out of more than 5,500 proposed or traditional ones; the chemical composition of a named mineral species may vary somewhat by the inclusion of small amounts of impurities. Specific varieties of a species sometimes have official names of their own. For example, amethyst is a purple variety of the mineral species quartz; some mineral species can have variable proportions of two or more chemical elements that occupy equivalent positions in the mineral's structure. Sometimes a mineral with variable composition is split into separate species, more or less arbitrarily, forming a mineral group. Besides the essential chemical composition and crystal structure, the description of a mineral species includes its common physical properties such as habit, lustre, colour, tenacity, fracture, specific gravity, fluorescence, radioactivity, as well as its taste or smell and its reaction to acid. Minerals are classified by key chemical constituents.
Silicate minerals comprise 90% of the Earth's crust. Other important mineral groups include the native elements, oxides, carbonates and phosphates. One definition of a mineral encompasses the following criteria: Formed by a natural process. Stable or metastable at room temperature. In the simplest sense, this means. Classical examples of exceptions to this rule include native mercury, which crystallizes at −39 °C, water ice, solid only below 0 °C. Modern advances have included extensive study of liquid crystals, which extensively involve mineralogy. Represented by a chemical formula. Minerals are chemical compounds, as such they can be described by fixed or a variable formula. Many mineral groups and species are composed of a solid solution. For example, the olivine group is described by the variable formula 2SiO4, a solid solution of two end-member species, magnesium-rich forsterite and iron-rich fayalite, which are described by a fixed chemical formula. Mineral species themselves could have a variable composition, such as the sulfide mackinawite, 9S8, a ferrous sulfide, but has a significant nickel impurity, reflected in its formula.
Ordered atomic arrangement. This means crystalline. An ordered atomic arrangement gives rise to a variety of macroscopic physical properties, such as crystal form and cleavage. There have been several recent proposals to classify amorphous substances as minerals; the formal definition of a mineral approved by the IMA in 1995: "A mineral is an element or chemical compound, crystalline and, formed as a result of geological processes." Abiogenic. Biogenic substances are explicitly excluded by the IMA: "Biogenic substances are chemical compounds produced by biological processes without a geological component and are not regarded as minerals. However, if geological processes were involved in the genesis of the compound the product can be accepted as a mineral."The first three general characteristics are less debated than the last two. Mineral classification schemes and their definitions are evolving to match recent advances in mineral science. Recent changes have included the addition of an organic class, in both the new Dana and the Strunz classification schemes.
The organic class includes a rare group of minerals with hydrocarbons. The IMA Commission on New Minerals and Mineral Names adopted in 2009 a hierarchical scheme for the naming and classification of mineral groups and group names and established seven commissions and four working groups to review and classify minerals into an official listing of their published names. According to these new r
A pagoda is a tiered tower with multiple eaves, built in traditions originating as stupa in historic South Asia and further developed in East Asia with respect to those traditions, common to Nepal, Japan, Vietnam, India, Sri Lanka and other parts of Asia. Some pagodas are used as Taoist houses of worship. Most pagodas were built to have a religious function, most Buddhist, were located in or near viharas. In some countries, the term may refer to other religious structures. In Vietnam and Cambodia, due to French translation, the English term pagoda is a more generic term referring to a place of worship, although pagoda is not an accurate word to describe a Buddhist vihara; the modern pagoda is an evolution of the stupa. Stupas are a tomb-like structure where sacred relics could be kept venerated; the architectural structure of the stupa has spread across Asia, taking on many diverse forms as details specific to different regions are incorporated into the overall design. Many Philippine bell towers are influenced by pagodas through Chinese workers hired by the Spaniards.
One proposed etymology is from a South Chinese pronunciation of the term for an eight-cornered tower, Chinese: 八角塔, reinforced by the name of a famous pagoda encountered by many early European visitors to China, the "Pázhōu tǎ", standing just south of Guangzhou at Whampoa Anchorage. Another proposed etymology is Persian butkada, from but, "idol" and kada, "temple, dwelling."Another etymology, found in many English language dictionaries, is modern English pagoda from Portuguese, from Sanskrit bhagavati, feminine of bhagavat, "blessed", from bhag, "good fortune". Yet another etymology of pagoda is from the Sinhala word dāgaba, derived from Sanskrit dhātugarbha or Pali dhātugabbha: "relic womb/chamber" or "reliquary shrine", i.e. a stupa, by way of Portuguese. The origin of the pagoda can be traced to the stupa; the stupa, a dome shaped monument, was used as a commemorative monument associated with storing sacred relics. In East Asia, the architecture of Chinese towers and Chinese pavilions blended into pagoda architecture also spreading to Southeast Asia.
The pagoda's original purpose was to sacred writings. This purpose was popularized due to the efforts of Buddhist missionaries, pilgrims and ordinary devotees to seek out and extol Buddhist relics. On the other side, the stupa emerged as a distinctive style of Newa architecture of Nepal and was adopted in Southeast and East Asia. Nepali architect Araniko shared his skills to build stupa buildings in China; these buildings became prominent. Chinese iconography is noticeable in Chinese pagoda as well as other East Asian pagoda architectures; the image of Gautama Buddha in the abhaya mudrā is noticeable in some Pagodas. Buddhist iconography can be observed throughout the pagoda symbolism. In an article on Buddhist elements in Han dynasty art, Wu Hung suggests that in these tombs, Buddhist symbolism was so well-incorporated into native Chinese traditions that a unique system of symbolism had been developed. Pagodas attract lightning strikes because of their height. Many pagodas have a decorated finial at the top of the structure, when made of metal, this finial, sometimes referred to as a "demon-arrester", can function as a lightning rod.
Pagodas come in many different sizes, as some may be small and others may be large. Pagodas traditionally have an odd number of levels, a notable exception being the eighteenth century pagoda designed by Sir William Chambers at the Royal Botanic Gardens, London; the pagodas in Myanmar, Thailand and Cambodia are different from Chinese and Japanese pagodas. Pagodas in those countries are derived from Dravidian architecture. Tiered towers with multiple eaves: Songyue Pagoda on Mount Song, China, built in 523. Mireuksa at Iksan, built in the early 7th century. Bunhwangsa at Gyeongju, built in 634. Xumi Pagoda at Zhengding, China, built in 636. Daqin Pagoda in China, built in 640. Hwangnyongsa Wooden nine-story pagoda on Hwangnyongsa, Korea, built in 645. Pagoda at Hōryū-ji, Nara, built in the 7th century. Giant Wild Goose Pagoda, built in Xi'an, China in 704 Small Wild Goose Pagoda, built in Xi'an, China in 709. Seokgatap on Bulguksa, Korea, built in 751. Dabotap on Bulguksa, Korea, built in 751. Tiger Hill Pagoda, built in 961 outside of Suzhou, China Lingxiao Pagoda at Zhengding, China, built in 1045.
Iron Pagoda of Kaifeng, built in 1049, during the Song dynasty. Liaodi Pagoda of Dingzhou, built in 1055 during the Song dynasty Pagoda of Fogong Temple, built in 1056 in Ying County, China. Pizhi Pagoda of Lingyan Temple, China, 11th century. Beisi Pagoda at Suzhou, China, built in 1162. Liuhe Pagoda of Hangzhou, built in 1165, during the Song dynasty. Ichijō-ji, Kasai, Hyōgo, built in 1171; the Porcelain Tower of Nanjing, built between 1402 and 1424, a wonder of the medieval world in Nanjing, China. Tsui Sing Lau Pagoda in Ping Shan, Hong Kong, built in 1486. Dragon and Tiger Pagodas in Kaohsiung, built in 1976. Seven-storey Pagoda in Chinese Garden at Jurong East, built in 1975. Pazhou Pagoda on Whampoa Island, China, built in 1600. Pagoda of the Celestial Lady, in Huế, built in 1601. Palsangjeon, a five-story pagoda at Beopjusa, Korea built in 1605. Tō-ji, the tallest wooden structure in Kyoto, built in 1644. Nyatapola at Bhaktapur, Kathmandu Valley built during 1701–1702; the Great Pagoda at Kew Gardens, London, UK, built in 1762.
Trấn Quốc Pagoda, Ha
A stalactite is a type of formation that hangs from the ceiling of caves, hot springs, or manmade structures such as bridges and mines. Any material, soluble, can be deposited as a colloid, or is in suspension, or is capable of being melted, may form a stalactite. Stalactites may be composed of lava, mud, pitch, sand and amberat. A stalactite is not a speleothem, though speleothems are the most common form of stalactite because of the abundance of limestone caves; the corresponding formation on the floor of the cave is known as a stalagmite. The most common stalactites are speleothems, they form through deposition of calcium carbonate and other minerals, precipitated from mineralized water solutions. Limestone is the chief form of calcium carbonate rock, dissolved by water that contains carbon dioxide, forming a calcium bicarbonate solution in underground caverns; the chemical formula for this reaction is: CaCO3 + H2O + CO2 → Ca2This solution travels through the rock until it reaches an edge and if this is on the roof of a cave it will drip down.
When the solution comes into contact with air the chemical reaction that created it is reversed and particles of calcium carbonate are deposited. The reversed reaction is: Ca2 → CaCO3 + H2O + CO2An average growth rate is 0.13 mm a year. The quickest growing stalactites are those formed by a constant supply of slow dripping water rich in calcium carbonate and carbon dioxide, which can grow at 3 mm per year; the drip rate must be slow enough to allow the CO2 to degas from the solution into the cave atmosphere, resulting in deposition of CaCO3 on the stalactite. Too fast a drip rate and the solution, still carrying most of the CaCO3, falls to the cave floor where degassing occurs and CaCO3 is deposited as a stalagmite. All limestone stalactites begin with a single mineral-laden drop of water; when the drop falls, it deposits the thinnest ring of calcite. Each subsequent drop that forms and falls deposits another calcite ring; these rings form a narrow, hollow tube known as a "soda straw" stalactite.
Soda straws can grow quite long, but are fragile. If they become plugged by debris, water begins flowing over the outside, depositing more calcite and creating the more familiar cone-shaped stalactite; the same water drops that fall from the tip of a stalactite deposit more calcite on the floor below resulting in a rounded or cone-shaped stalagmite. Unlike stalactites, stalagmites never start out as hollow "soda straws". Given enough time, these formations can meet and fuse to create pillars of calcium carbonate known as a "column". Stalactite formation begins over a large area, with multiple paths for the mineral rich water to flow; as minerals are dissolved in one channel more than other competing channels, the dominant channel begins to draw more and more of the available water, which speeds its growth resulting in all other channels being choked off. This is one reason; the larger the formation, the greater the interformation distance. Another type of stalactite is formed in lava tubes; the mechanism of formation is the deposition of material on the ceilings of caves, however with lava stalactites formation happens quickly in only a matter of hours, days, or weeks, whereas limestone stalactites may take up to thousands of years.
A key difference with lava stalactites is that once the lava has ceased flowing, so too will the stalactites cease to grow. This means; the generic term lavacicle has been applied to lava stalactites and stalagmites indiscriminately and evolved from the word icicle. Like limestone stalactites, they can leave lava drips on the floor that turn into lava stalagmites and may fuse with the corresponding stalactite to form a column. Shark tooth stalactites, it may begin as a small driblet of lava from a semi-solid ceiling, but grows by accreting layers as successive flows of lava rise and fall in the lava tube and recoating the stalactite with more material. They can vary from a few millimeters to over a meter in length. Splash stalactites As lava flows through a tube, material will be splashed up on the ceiling and ooze back down, hardening into a stalactite; this type of formation results in a irregularly shaped stalactite, looking somewhat like stretched taffy. They may be of a different color than the original lava that formed the cave.
Tubular lava stalactites When the roof of a lava tube is cooling, a skin will form that traps semi-molten material inside. Trapped gases force lava to extrude out through small openings that result in hollow, tubular stalactites analogous to the soda straws formed as depositional speleothems in solution caves, The longest known is 2 meters in length; these are common in Hawaiian lava tubes and are associated with a drip stalagmite that forms below as material is carried through the tubular stalactite and piles up on the floor beneath. Sometimes the tubular form collapses near the distal end, most when the pressure of escaping gases decreased and still-molten portions of the stalactites deflated and cooled; these tubular stalactites will acquire a twisted, vermiform appearance as bits of lava crystallize and force the flow in different directions. These tubular lava helictites may be influenced by air
Carbonated water or soda water is water containing dissolved carbon dioxide gas, either artificially injected under pressure or occurring due to natural geological processes. Carbonation causes small bubbles to form. Common forms include sparkling natural mineral water, club soda, commercially produced sparkling water. Club soda, sparkling mineral water and many other sparkling waters contain added or dissolved minerals such as potassium bicarbonate, sodium bicarbonate, sodium citrate, or potassium sulfate; these occur in some mineral waters but are commonly added artificially to man-made waters to mimic a natural flavor profile. Various carbonated waters are sold in bottles and cans, with some produced on demand by commercial carbonation systems in bars and restaurants, or made at home using a carbon dioxide cartridge, it is thought the first person to aerate water with carbon dioxide was William Brownrigg in 1740, although he never published a paper. Carbonated water was independently accidentally invented by Joseph Priestley in 1767 when he discovered a method of infusing water with carbon dioxide after suspending a bowl of water above a beer vat at a brewery in Leeds, England.
He wrote of the "peculiar satisfaction" he found in drinking it, in 1772 he published a paper entitled Impregnating Water with Fixed Air. Priestley’s apparatus, which featured a bladder between the generator and the absorption tank to regulate the flow of carbon dioxide, was soon joined by a wide range of others, but it wasn’t until 1781 that carbonated water began being produced on a large scale with the establishment of companies specialized in producing artificial mineral water; the first factory was built by Thomas Henry of England. Henry replaced the bladder in Priestley’s system with large bellows. While Priestley is regarded as “the father of the soft drink,” he did not benefit financially from his invention, he did however receive scientific recognition when the Council of the Royal Society “were moved to reward its discoverer with the Copley Medal” in 1772. Natural and man-made carbonated waters may contain a small amount of sodium chloride, sodium citrate, sodium bicarbonate, potassium bicarbonate, potassium citrate, potassium sulfate, or disodium phosphate, depending on the product.
These occur in mineral waters but are added artificially to commercially produced waters to mimic a natural flavor profile. Artesian wells in such places as Mihalkovo in the Bulgarian Rhodope Mountains, Medžitlija in North Macedonia, most notably in Selters in the German Taunus mountains, produce effervescent mineral waters. By itself, carbonated water appears to have little impact on health. While carbonated water is somewhat acidic, this acidity can be neutralized by saliva. A study found that sparkling mineral water is more erosive to teeth than non-carbonated water but is about 100 times less erosive to teeth than are soft drinks. Carbonated water may increase irritable bowel syndrome symptoms of bloating and gas due to the release of carbon dioxide in the digestive tract, it does not appear to have an effect on gastroesophageal reflux disease. There is tentative evidence that carbonated water may help with constipation among people who have had a stroke. Carbonated water such as club soda or sparkling water is defined in US law as a food of minimal nutritional value if minerals, vitamins, or artificial sweeteners have been added to it.
Carbon dioxide gas dissolved in water at a low concentration creates carbonic acid according to the following reaction: H 2 O + CO 2 ↽ − − ⇀ H 2 CO 3 The acid gives carbonated water a tart flavor. The pH level between 3 and 4 is in between apple juice and orange juice in acidity, but much less acidic than the acid in the stomach. A normal, healthy human body maintains pH equilibrium via acid–base homeostasis and will not be materially adversely affected by consumption of plain carbonated water. Alkaline salts, such as sodium bicarbonate, potassium bicarbonate, or potassium citrate, will increase pH; the amount of a gas that can be dissolved in water is described by Henry's Law. In the carbonization process water is chilled, optimally to just above freezing, to maximize the amount of carbon dioxide that can be dissolved in it. Higher gas pressure and lower temperature cause more gas to dissolve in the liquid; when the temperature is raised or the pressure is reduced, carbon dioxide effervesces, thereby escaping from the solution.
Many alcoholic drinks, such as beer and champagne, were carbonated through the fermentation process for centuries. In 1662 Christopher Merret was creating'sparkling wine'. William Brownrigg was the first to produce artificial carbonated water, in the early 1740s, by using carbon dioxide taken from mines. In 1750 the Frenchman Gabriel François Venel produced artificial carbonated water, though he misunderstood the nature of the gas that caused the carbonation. In 1764, Irish chemist Dr. Macbride infused water with carbon dioxide as part of a series of experiments on fermentation and putrefaction. In 1766 Henry Cavendish devised an aerating apparatus that would inspire Joseph Priestley to carry out his own experiments with regards to carbonated waters. Ca