Flint is a hard, sedimentary cryptocrystalline form of the mineral quartz, categorized as the variety of chert that occurs in chalk or marly limestone. Flint was widely used historically to make stone tools and start fires.
It occurs chiefly as nodules and masses in sedimentary rocks, such as chalks and limestones.  Inside the nodule, flint is usually dark grey, black, green, white or brown in colour, and often has a glassy or waxy appearance. A thin layer on the outside of the nodules is usually different in colour, typically white and rough in texture. The nodules can often be found along streams and beaches.
Flint breaks and chips into sharp edged pieces, making it useful for knife blades and other cutting tools. The use of flint to make stone tools dates back millions of years, and flint's extreme durability has made it possible to accurately date its use over this time. Flint is one of the primary materials used to define the Stone Age.
During the Stone Age, access to flint was so important for survival that people would travel or trade to obtain flint. Flint Ridge in Ohio was an important source of flint and Native Americans extracted the flint from hundreds of quarries along the ridge. This "Ohio Flint" was traded across the eastern United States and has been found as far west as the Rocky Mountains and south around the Gulf of Mexico. 
When struck against steel, flint will produce enough sparks to ignite a fire with the correct tinder, or gunpowder used in weapons. Although it has been superseded in these uses by different processes (the percussion cap), or materials, (ferrocerium), "flint" has lent its name as generic term for a fire starter.
The exact mode of formation of flint is not yet clear, but it is thought that it occurs as a result of chemical changes in compressed sedimentary rock formations, during the process of diagenesis. One hypothesis is that a gelatinous material fills cavities in the sediment, such as holes bored by crustaceans or molluscs and that this becomes silicified. This hypothesis certainly explains the complex shapes of flint nodules that are found. The source of dissolved silica in the porous media could be the spicules of silicious sponges.  Certain types of flint, such as that from the south coast of England, contain trapped fossilised marine flora. Pieces of coral and vegetation have been found preserved like amber inside the flint. Thin slices of the stone often reveal this effect.
Flint sometimes occurs in large flint fields in Jurassic or Cretaceous beds, for example, in Europe. Puzzling giant flint formations known as paramoudra and flint circles are found around Europe but especially in Norfolk, England on the beaches at Beeston Bump and West Runton. 
The "Ohio flint" is the official gemstone of Ohio state. It is formed from limey debris that was deposited at the bottom of inland Paleozoic seas hundreds of millions of years ago that hardened into limestone and later became infused with silica. The flint from Flint Ridge is found in many hues like red, green, pink, blue, white and gray, with the color variations caused by minute impurities of iron compounds.
Flint can be coloured: sandy brown, medium to dark gray, black, reddish brown or an off-white grey. 
Flint was used in the manufacture of tools during the Stone Age as it splits into thin, sharp splinters called flakes or blades (depending on the shape) when struck by another hard object (such as a hammerstone made of another material). This process is referred to as knapping. The process of making tools this way is called "flintknapping".
Flint mining is attested since the Palaeolithic, 3,300,000 years ago, but became more common since the Neolithic (Michelsberg culture, Funnelbeaker culture). In Europe, some of the best toolmaking flint has come from Belgium (Obourg, flint mines of Spiennes), the coastal chalks of the English Channel, the Paris Basin, Thy in Jutland (flint mine at Hov), the Sennonian deposits of Rügen, Grimes Graves in England, the Upper Cretaceous chalk formation of Dobruja and the lower Danube (Balkan flint), the Cenomanian chalky marl formation of the Moldavian Plateau (Miorcani flint) and the Jurassic deposits of the Kraków area and Krzemionki in Poland, as well as of the Lägern (silex) in the Jura Mountains of Switzerland.
In 1938, a project of the Ohio Historical Society, under the leadership of H. Holmes Ellis began to study the flintknapping "methods and techniques" of Native Americans. Like past studies, this work involved experimenting with actual flintknapping techniques by creation of stone tools through the use of techniques like direct freehand percussion, freehand pressure and pressure using a rest. Other scholars who have conducted similar experiments and studies include William Henry Holmes, Alonzo W. Pond, Sir Francis H. S. Knowles and Don Crabtree.
To combat fragmentation, flint/chert may be heat-treated, being slowly brought up to a temperature of 150 to 260 °C (300 to 500 °F) for 24 hours, then slowly cooled to room temperature. This makes the material more homogeneous and thus more "knappable" and produces tools with a cleaner, sharper cutting edge. Heat treating was known to stone age artisans.
When struck against steel, a flint edge produces sparks. The hard flint edge shaves off a particle of the steel that exposes iron, which reacts with oxygen from the atmosphere and can ignite the proper tinder.
Prior to the wide availability of steel, rocks of pyrite (FeS2) would be used along with the flint, in a similar (but more time-consuming) way. These methods remain popular in woodcraft, bushcraft, and amongst people practising traditional fire-starting skills. 
A later, major use of flint and steel was in the flintlock mechanism, used primarily in flintlock firearms, but also used on dedicated fire-starting tools. A piece of flint held in the jaws of a spring-loaded hammer, when released by a trigger, strikes a hinged piece of steel ("frizzen") at an angle, creating a shower of sparks and exposing a charge of priming powder. The sparks ignite the priming powder and that flame, in turn, ignites the main charge, propelling the ball, bullet, or shot through the barrel. While the military use of the flintlock declined after the adoption of the percussion cap from the 1840s onward, flintlock rifles and shotguns remain in use amongst recreational shooters.
Flint and steel used to strike sparks were superseded by ferrocerium (sometimes referred to as "flint", although not true flint, "mischmetal", "hot spark", "metal match", or "fire steel"). This man-made material, when scraped with any hard, sharp edge, produces sparks that are much hotter than obtained with natural flint and steel, allowing use of a wider range of tinders. Because it can produce sparks when wet and can start fires when used correctly, ferrocerium is commonly included in survival kits. Ferrocerium is used in many cigarette lighters, where it is referred to as "a flint".
Flint's utility as a fire starter is due to its property of uneven expansion under heating, causing it to fracture, sometimes violently, during heating. This tendency is enhanced by the fact that most samples of flint contain impurities that may expand to a greater or lesser degree than the surrounding stone, and is similar to the tendency of glass to shatter when exposed to heat, and can become a drawback when flint is used as a building material. 
Flint, knapped or unknapped, has been used from antiquity (for example at the Late Roman fort of Burgh Castle in Norfolk) up to the present day as a material for building stone walls, using lime mortar, and often combined with other available stone or brick rubble. It was most common in parts of southern England, where no good building stone was available locally, and brick-making not widespread until the later Middle Ages. It is especially associated with East Anglia, but also used in chalky areas stretching through Hampshire, Sussex, Surrey and Kent to Somerset.
Flint was used in the construction of many churches, houses, and other buildings, for example the large stronghold of Framlingham Castle. Many different decorative effects have been achieved by using different types of knapping or arrangement and combinations with stone (flushwork), especially in the 15th and early 16th centuries.
Flint pebbles are used as the media in ball mills to grind glazes and other raw materials for the ceramics industry.  The pebbles are hand-selected based on colour; those having a tint of red, indicating high iron content, are discarded. The remaining blue-grey stones have a low content of chromophoric oxides and so are less deleterious to the colour of the ceramic composition after firing.
Until recently flint was also an important raw material in clay-based ceramic bodies produced in the UK. In preparation for use flint pebbles, frequently sourced from the coasts of South-East England or Western France, were calcined to around 1,000 °C. This heat process both removed organic impurities and induced certain physical reactions, including converting some of the silica to cristobalite. After calcination the flint pebbles were milled to a fine particle size. However, the use of flint has now been superseded by quartz. Because of the historical use of flint, the word "flint" is used by some potters, especially in the US, to refer to siliceous materials that are not flint.
On June 21, 2017, airport police Lt. Jeff Neville was stabbed in the neck at Bishop International Airport in the city of Flint, Michigan, in the United States. The man, Amor Ftouhi, reportedly yelled "Allahu akbar" during the attack and was travelling on a Canadian passport. Bomb sniffing dogs searched the evacuated airport, finding nothing. He was charged with violence at an international airport and interfering with airport security. He was later charged with committing an act of terrorism transcending national boundaries. Found guilty of all three charges in November 2018, he was sentenced to life in prison in April 2019.Captain Flint
Captain J. Flint is a fictional 18th-century pirate captain who features in a number of novels, television series, and films. The original character was created by the Scottish writer Robert Louis Stevenson (1850-1894). Flint first appears in the classic adventure yarn Treasure Island, which was first serialised in a children's magazine in 1881, and later published as a novel in 1883.Chert
Chert ( ) is a hard, fine-grained sedimentary rock composed of crystals of quartz (silica) that are very small (microcrystalline or cryptocrystalline). Quartz (silica) is the mineral form of silicon dioxide (SiO2). Chert is often of biological origin (organic) but may also occur inorganically as a chemical precipitate or a diagenetic replacement (e.g., petrified wood). Geologists use chert as a generic name for any type of microcrystalline or cryptocrystalline quartz.
Chert is usually of biological origin, being the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor, and which contains the silicon skeletal remains of diatoms, silicoflagellates, and radiolarians. Depending on its origin, it can contain either microfossils, small macrofossils, or both. It varies greatly in color (from white to black), but most often manifests as gray, brown, grayish brown and light green to rusty red (occasionally dark green too); its color is an expression of trace elements present in the rock, and both red and green are most often related to traces of iron (in its oxidized and reduced forms respectively).Flint, Michigan
Flint is the largest city and seat of Genesee County, Michigan, United States. Located along the Flint River, 66 miles (106 km) northwest of Detroit, it is a principal city within the region known as Mid Michigan. According to the 2010 census, Flint has a population of 102,434, making it the seventh largest city in Michigan. The Flint metropolitan area is located entirely within Genesee County. It is the fourth largest metropolitan area in Michigan with a population of 425,790 in 2010. The city was incorporated in 1855.
Flint was founded as a village by fur trader Jacob Smith in 1819 and became a major lumbering area on the historic Saginaw Trail during the 19th century. From the late 19th century to the mid 20th century, the city was a leading manufacturer of carriages and later automobiles, earning it the nickname "Vehicle City". General Motors (GM) was founded in Flint in 1908, and the city grew into an automobile manufacturing powerhouse for GM's Buick and Chevrolet divisions after World War II up until the early 1980s recession. Flint was also the home of the Flint Sit-Down Strike of 1936–37 that played a vital role in the formation of the United Automobile Workers.
Since the late 1960s, Flint has faced several crises. The city sank into a deep economic depression after GM significantly downsized its workforce in the area from a 1978 high of 80,000 to under 8,000 by 2010. From 1960 to 2010, the population of the city nearly halved from 196,940 to 102,434. In the mid-2000s, Flint became known for its high crime rates and has repeatedly been ranked among the most dangerous cities in the United States. The city was under a state of financial emergency from 2002–2004 and again from 2011–2015. Since 2014, the city has faced a major public health emergency due to lead contamination in the local water supply that has affected thousands of residents, as well as an outbreak of Legionnaires' disease due to tainted water.Flint Hills
The Flint Hills, historically known as Bluestem Pastures or Blue Stem Hills, are a region in eastern Kansas and north-central Oklahoma named for the abundant residual flint eroded from the bedrock that lies near or at the surface. It consists of a band of hills stretching from Kansas to Oklahoma, extending from Marshall and Washington Counties in the north to Cowley County, Kansas and Kay and Osage Counties in Oklahoma in the south, to Geary and Shawnee Counties west to east. Oklahomans generally refer to the same geologic formation as the Osage Hills or "the Osage."
The Flint Hills Ecoregion is designated as a distinct region because it has the most dense coverage of intact tallgrass prairie in North America. Due to its rocky soil, the early settlers were unable to plow the area, resulting in the prevalence of cattle ranches as opposed to the crop land more typical of the Great Plains. These ranches rely on annual controlled burns conducted by ranchers every spring to renew the prairie grasses for cattle to graze. This has created in an unusual alliance between the native ecosystem of the Flint Hills and the people who use it.
The Flint Hills Discovery Center, a science and history museum focusing on the Flint Hills, opened in Manhattan, Kansas, in April 2012.Flint water crisis
The Flint water crisis began in 2014, after the drinking water source for the city of Flint, Michigan was changed from Lake Huron and the Detroit River to a less costly source of the Flint River. Due to insufficient water treatment, lead leached from water pipes into the drinking water, exposing over 100,000 residents to elevated lead levels.
After a pair of scientific studies proved lead contamination was present in the water supply, a federal state of emergency was declared in January 2016 and Flint residents were instructed to use only bottled or filtered water for drinking, cooking, cleaning, and bathing. Some officials asserted as of early 2017 that the water quality had returned to acceptable levels, but as of January 2019, residents and officials still express doubt. All the lead pipes are being replaced, which is expected to be completed in 2019. There are an estimated 2,500 lead service lines still in place as of April 2019.Flintlock
Flintlock is a general term for any firearm that uses a flint striking ignition mechanism. The term may also apply to a particular form of the mechanism itself, also known as the true flintlock, that was introduced in the early 17th century, and rapidly replaced earlier firearm-ignition technologies, such as the matchlock, the wheellock, and the earlier flintlock mechanisms.
The true flintlock continued to be in common use for over two centuries, replaced by percussion cap and, later, the cartridge-based systems in the early-to-mid 19th century. Although long superseded by modern firearms, flintlock weapons enjoy continuing popularity with black-powder shooting enthusiasts.Genesee County, Michigan
Genesee County is a county in the U.S. state of Michigan. As of the 2010 census, the population was 425,790, making it the fifth-most populous county in Michigan. The county seat and population center is Flint (birthplace of General Motors). Genesee County is considered to be a part of the greater Mid Michigan area.
The county was named after Genesee County, New York. Genesee County comprises the Flint, MI Metropolitan Statistical Area and is included in the Detroit-Warren-Ann Arbor, MI Combined Statistical Area. Many local place names in the county, including the county itself, are also from New York and Pennsylvania, reflecting the pattern of settlement. A major attraction for visitors is Crossroads Village, a living history village north of Flint.
Genesee is noted for having had the fossil of an ancient whale known as Balaenoptera Lacepede unearthed in Thetford Township during quarry work and estimated at 11,000 years old.Grime's Graves
Grime's Graves is a large Neolithic flint mining complex in Norfolk, England. It lies 8 km (5.0 mi) north east from Brandon, Suffolk in the East of England. It was worked between c. 2600 and c. 2300 BC, although production may have continued well into the Bronze and Iron Ages (and later) owing to the low cost of flint compared with metals. Flint was much in demand for making polished stone axes in the Neolithic period. Much later, when flint had been replaced by metal tools, flint nodules were in demand for other uses, such as for building and as strikers for muskets.
The scheduled monument extends over an area of some 37 ha (91 acres) and consists of at least 433 shafts dug into the natural chalk to reach seams of flint. The largest shafts are more than 14 m (46 ft) deep and 12 m (39 ft) in diameter at the surface. It has been calculated that more than 2,000 tonnes of chalk had to be removed from the larger shafts, taking 20 men around five months, before stone of sufficient quality was reached. An upper 'topstone' and middle 'wallstone' seam of flint was dug through on the way to the deeper third 'floorstone' seam which most interested the miners. The site is managed by English Heritage and can be visited.
The site is also a biological and geological Site of Special Scientific Interest and a Geological Conservation Review site. It is part of the Breckland Special Area of Conservation and Special Protection Area.Keith Flint
Keith Charles Flint (17 September 1969 – 4 March 2019) was an English vocalist, dancer and motorcycle racer. He was a founding member of the electronic dance act the Prodigy. Starting out as a dancer, he became the frontman of the group and performed on the group's two UK number one singles, "Firestarter" and "Breathe" both released in 1996. He was also the lead singer of his own band, Flint. He owned a motorcycle racing team, Team Traction Control, which won three Isle of Man TT races in 2015 and competed in the British Supersport Championship.Knapping
Knapping is the shaping of flint, chert, obsidian or other conchoidal fracturing stone through the process of lithic reduction to manufacture stone tools, strikers for flintlock firearms, or to produce flat-faced stones for building or facing walls, and flushwork decoration. The original Germanic term "knopp" meant strike, shape, or work, so it could theoretically have referred equally well to making a statue or dice. Modern usage is more specific, referring almost exclusively to the hand-tool pressure-flaking process pictured.Koch Industries
Koch Industries, Inc. is an American multinational corporation based in Wichita, Kansas. Its subsidiaries are involved in the manufacturing, refining, and distribution of petroleum, chemicals, energy, fiber, intermediates and polymers, minerals, fertilizers, pulp and paper, chemical technology equipment, ranching, finance, commodities trading, and investing. Koch owns Invista, Georgia-Pacific, Molex, Flint Hills Resources, Koch Pipeline, Koch Fertilizer, Koch Minerals, Matador Cattle Company, and Guardian Industries. The firm employs 120,000 people in 60 countries, with about half of its business in the United States. The company is the largest landowner in the Athabasca oil sands.With annual revenues of $110 billion, the company is the second largest privately held company in the United States after Cargill. In 2007, it was ranked as the largest privately held company. If Koch Industries had been a public company in 2013, it would have ranked 17th in the Fortune 500.The company was founded by its namesake, Fred C. Koch, in 1940 after he developed an innovative crude oil refining process. Fred C. Koch died in 1967 and his majority interest in the company was split amongst his four sons. In June 1983, after a bitter legal and boardroom battle, the stakes of Frederick R. Koch and William "Bill" Koch were bought out for $1.1 billion and Charles Koch and David Koch became majority owners in the company. Charles and David Koch each own 42% of the company; trusts for the benefit of Elaine Tettemer Marshall, the daughter in-law of J. Howard Marshall and Anna Nicole Smith, and her children, Preston Marshall and E. Pierce Marshall Jr., own 16% of the company.The company has used its freedom from the pressures of public markets to make long-term bets, and Charles Koch has stated that the company would go public "over my dead body".Metro Detroit
The Detroit metropolitan area, often referred to as Metro Detroit, is a major metropolitan area in the U.S. State of Michigan, consisting of the city of Detroit and its surrounding area. There are varied definitions of the area, including the official statistical areas designated by the Office of Management and Budget, a federal agency of the United States. Metro Detroit is known for its automotive heritage, arts, entertainment, popular music, and sports. The area includes a variety of natural landscapes, parks, and beaches, with a recreational coastline linking the Great Lakes. Metro Detroit also has one of the largest metropolitan economies in the U.S., with seventeen Fortune 500 companies.Sandman (Marvel Comics)
Sandman (Flint Marko) is a fictional character appearing in American comic books published by Marvel Comics. A shapeshifter endowed through an accident with the ability to turn himself into sand, he began as a villain and later became an ally of Spider-Man.
The character has been adapted into various other media incarnations of Spider-Man. In film, Thomas Haden Church portrays Sandman in Spider-Man 3.
In 2009, Sandman was ranked as IGN's 72nd Greatest Comic Book Villain of All Time.Stone tool
A stone tool is, in the most general sense, any tool made either partially or entirely out of stone. Although stone tool-dependent societies and cultures still exist today, most stone tools are associated with prehistoric (particularly Stone Age) cultures that have become extinct. Archaeologists often study such prehistoric societies, and refer to the study of stone tools as lithic analysis. Ethnoarchaeology has been a valuable research field in order to further the understanding and cultural implications of stone tool use and manufacture.Stone has been used to make a wide variety of different tools throughout history, including arrow heads, spearpoints and querns. Stone tools may be made of either ground stone or chipped stone, and a person who creates tools out of the latter is known as a flintknapper.
Chipped stone tools are made from cryptocrystalline materials such as chert or flint, radiolarite, chalcedony, obsidian, basalt, and quartzite via a process known as lithic reduction. One simple form of reduction is to strike stone flakes from a nucleus (core) of material using a hammerstone or similar hard hammer fabricator. If the goal of the reduction strategy is to produce flakes, the remnant lithic core may be discarded once it has become too small to use. In some strategies, however, a flintknapper reduces the core to a rough unifacial or bifacial preform, which is further reduced using soft hammer flaking techniques or by pressure flaking the edges.
More complex forms of reduction include the production of highly standardized blades, which can then be fashioned into a variety of tools such as scrapers, knives, sickles and microliths. In general terms, chipped stone tools are nearly ubiquitous in all pre-metal-using societies because they are easily manufactured, the tool stone is usually plentiful, and they are easy to transport and sharpen.Terry Crews
Terry Alan Crews (born July 30, 1968) is an American actor, comedian, activist, artist, and former American football player. Crews played Julius Rock on the UPN/CW sitcom Everybody Hates Chris. He previously hosted the US version of the game show Who Wants to Be a Millionaire and starred in the BET reality series The Family Crews. He appeared in films such as Friday After Next (2002), White Chicks (2004), Idiocracy (2006), and the Expendables series. Since 2013, he has played NYPD Sergeant Terry Jeffords in the sitcom Brooklyn Nine-Nine. He is currently hosting America's Got Talent in 2019, following his involvement in the same role for the program's spin-off series America's Got Talent: The Champions from January 2019.
Crews played as a defensive end and linebacker in the National Football League (NFL) for the Los Angeles Rams, San Diego Chargers, and Washington Redskins, as well as in the World League of American Football with Rhein Fire, and college football at Western Michigan University.
Crews, a public advocate for women's rights and activist against sexism, has shared stories of the abuse his family endured at the hands of his violent father. He was included among the group of people named as Time Magazine's Person of the Year in 2017 for going public with stories of sexual assault.University of Michigan–Flint
The University of Michigan-Flint (commonly referred to as UM-Flint) is a public university in Flint, Michigan. It is one of the two University of Michigan regional campuses (the other is in Dearborn).WFBE
WFBE (95.1 FM, "Nash FM 95-1") is a radio station broadcasting a country music format. Licensed to Flint, Michigan, it began broadcasting in 1953. Its studios are located south of the Flint city limits in Mundy Township and its transmitter is south of Flint in Burton.
The station was owned by the Flint Board of Education and the studios were on the campus of Flint Central High School for many years. The format was a public station which also consisted of news and education.WTRX
WTRX (1330 AM, "Sports XTRA 1330") is an American radio station broadcasting a sports radio format in Flint, Michigan. It is the Flint affiliate for the Detroit Lions, Detroit Tigers, Michigan Wolverines, and ESPN Radio. Its studios are located south of the Flint city limits in Mundy Township and its transmitter is south of Flint in Burton.