James Prescott Joule: …unit of heat, called the mechanical equivalent of heat. He used four increasingly accurate methods of determining this value. By using different materials, he also established that heat was a form of energy regardless of the substance that was heated. In 1852 Joule and William Thomson (later Lord Kelvin) discovered…

Sandra Bullock: …in the broad, raunchy comedy The Heat. Later that year she starred with George Clooney in Gravity, an acclaimed drama about astronauts struggling to survive after their spacecraft has been destroyed; Bullock earned an Oscar nomination for her performance. She then voiced the villainous Scarlett Overkill in the animated comedy…

construction: Glass as a building material: Heat-mirror glass, which has a transparent coating that admits the short-wavelength radiation from the sun but tends to reflect the longer-wavelength radiation from within occupied spaces, was introduced in 1984; when combined with double glazing, its insulating value approaches that of a wall.

adhesive: Hot-melt adhesives: Hot-melt adhesives are employed in many nonstructural applications. Based on thermoplastic resins, which melt at elevated temperatures without degrading, these adhesives are applied as hot liquids to the adherend. Commonly used polymers include polyamides, polyesters, ethylene-vinyl acetate, polyurethanes, and a variety of block…

rocket and missile system: Passive: …successful passive homing munitions were “heat-seeking” air-to-air missiles that homed onto the infrared emissions of jet engine exhausts. The first such missile to achieve wide success was the AIM-9 Sidewinder developed by the U.S. Navy in the 1950s. Many later passive homing air-to-air missiles homed onto ultraviolet radiation as well,…

sprinkler system: …closed orifice is opened by heat from a fire. Modern versions use a fusible link or a bulb containing chemicals, which breaks at about 160° F (70° C) to open the orifice. Modern sprinkler heads are designed to direct a spray downward. Most sprinkler systems are wet-head—i.e., they use pipes…

rattlesnake: …group named for the small heat-sensing pit between each eye and nostril that aids in hunting. The pits provide the snake with stereoscopic heat “vision,” enabling them to detect and accurately strike a living target in complete darkness. Most rattlesnakes live in arid habitats and are nocturnal, hiding during the…

textile: Tentering, crabbing, and heat-setting: …fibres it is sometimes called heat-setting, a term also applied to the permanent setting of pleats, creases, and special surface effects.

ectotherm: …of heat stress, ectotherms release heat-shock proteins, which help stabilize other proteins and thus prevent their denaturation (modification of a protein’s molecular structure).

heat-treating, changing the properties of materials such as metals or glass by processes involving heating. It is used to harden, soften, or modify other properties of materials that have different crystal structures at low and high temperatures. The type of transformation depends on the

electric heater, device for heating rooms that converts electric current to heat by means of resistors that emit radiant energy. Resistors may be composed of metal-alloy wire, nonmetallic carbon compounds, or printed circuits. Heating elements may have exposed resistor coils mounted on insulators,

heath, (genus Erica), genus of about 800 species of low evergreen shrubs of the family Ericaceae. Most heath species are indigenous to South Africa, where they are especially diverse in the southwestern Cape region. Some also occur in the Mediterranean region and in northern Europe, and species

scrubland: Ecological importance of fire to scrubland communities: …coastal scrublands in eastern Australia, Banksia ericifolia, is eliminated not only if an area is burned more often than every fifth year—the time taken for seedlings to set their first seed—but also if it is burned less often than every 40 years—the plant’s life span.

Ericaceae, the heath family of flowering plants (order Ericales), comprising 126 genera and some 4,000 species. Ericaceae is made up mostly of shrubs and small trees, and its members are widely distributed, extending into the subarctic and along mountain chains through the tropics. A large

Ericales, rhododendron order of flowering plants, containing 22 families, 346 genera, and more than 12,000 species. The relationships of the order are unclear. Together with Cornales, it is placed as a basal asterid in the Angiosperm Phylogeny Group IV (APG IV) botanical classification system (see

Colossus: How Colossus was designed: …Newmanry’s first analytic machine, “Heath Robinson,” employed photoelectric technology to read two punched paper tapes simultaneously, at a rate of 1,000–2,000 characters per second. One tape contained the message to be broken, and the other contained possible sequences of key letters (in teleprinter code). Named after a famous British…

bath chair: It was devised by James Heath, of Bath, Eng., about 1750. For the next three-quarters of a century it rivaled the sedan chair and ultimately superseded it as a form of conveyance in Great Britain. The most common variety was supported on two wheels joined by an axle beneath…

Sarah Palin is an American politician who served as governor of Alaska (2006–09) and was selected by Sen. John McCain to serve as his vice presidential running mate in the 2008 U.S. presidential election. She was the first woman to appear on a Republican presidential ticket. For coverage of the

Sir Edward Heath was the Conservative prime minister of Great Britain from 1970 to 1974. Although he was of modest origins, Heath was educated at Oxford, where he was elected president of the University Conservative Association in 1937. In 1938, as chairman of the Federation of University

Sir Edward Heath was the Conservative prime minister of Great Britain from 1970 to 1974. Although he was of modest origins, Heath was educated at Oxford, where he was elected president of the University Conservative Association in 1937. In 1938, as chairman of the Federation of University

Thales’ rectangle: …proofs survives, the English mathematician Thomas Heath (1861–1940) proposed what is now known as Thales’ rectangle as a proof of theorem 5 that would have been consistent with what was known in Thales’ era.

Bil and Cora Baird: …the master of ceremonies; and Heathcliff, the talking horse. Bil Baird trained a generation of younger puppeteers, including the creator of the Muppets, Jim Henson, and many of Henson’s associates. He was also the author of The Art of the Puppet (1965), a classic exposition of the field.

Heathcliff, fictional character, the brooding protagonist of Emily Brontë’s romantic novel Wuthering Heights

John Heathcoat was a pioneering English inventor of lace-making machinery. One of Heathcoat’s machines (patented in 1809), the most expensive and complex textile machine then in existence, simulated the movements of the bobbins in the hands of the pillow-lace workers, producing an exact imitation

Joyce Wethered was a golfer who was widely regarded as the greatest British woman player of her day. Wethered and her brother Roger, who tied for the British Open title in 1921 but lost the play-off, learned the game as children. She was British Ladies’ Open champion four times (1922, 1924, 1925,

textile: Net and lace making: In the Heathcot, or bobbinet, machine, warp threads were arranged so that the threads moved downward as the beams unwound. Other threads were wound on thin, flat spools or bobbins held in narrow carriages that could move in a groove or comb in two rows. The carriages…

tennis: Origin and early years: After J.M. Heathcote, a distinguished real tennis player, developed a better tennis ball of rubber covered with white flannel, the MCC in 1875 established a new, standardized set of rules for tennis.

paganism, Christian term used to designate those religions that do not worship the God of Abraham, the figure central to both Christianity and to other Abrahamic religions like Judaism and Islam. Christians have used the terms paganism and pagan, which typically carry pejorative connotations, to

Heathenry, a modern Pagan, or Neo-Pagan, religion. Its followers, Heathens, are inspired by the pre-Christian religions of Europe’s linguistically Germanic societies—most commonly those that spoke Old Norse. Heathens have assembled their new religion from a range of historical and archaeological

Bret Harte: …(1870), better known as “The Heathen Chinee,” although it attracted national attention in a manner unintended by Harte, who claimed that its satirical story—about two men, Bill Nye and Ah Sin, trying to cheat each other at cards—showed a form of racial equality. Instead, the poem was taken up…

paganism, Christian term used to designate those religions that do not worship the God of Abraham, the figure central to both Christianity and to other Abrahamic religions like Judaism and Islam. Christians have used the terms paganism and pagan, which typically carry pejorative connotations, to

Heathenry, a modern Pagan, or Neo-Pagan, religion. Its followers, Heathens, are inspired by the pre-Christian religions of Europe’s linguistically Germanic societies—most commonly those that spoke Old Norse. Heathens have assembled their new religion from a range of historical and archaeological

heather, (Calluna vulgaris), low evergreen shrub of the heath family (Ericaceae), widespread in western Europe and Asia, North America, and Greenland. It is the chief vegetation on many wastelands of northern and western Europe. The young juicy shoots and the seeds of heather are the principal food

Matthew Weiner: …2017 Weiner published the novella Heather, the Totality, about a wealthy Manhattan couple fixated on their daughter, who in turn becomes the target of a sociopath. The following year he created The Romanoffs, an Amazon series in which each episode follows a different cast of characters who believe they are…

Winona Ryder: …the critically acclaimed black comedy Heathers (1988); her portrayal of the female protagonist, Veronica Sawyer, was well received. Ryder was subsequently cast in other prominent roles, including reuniting with Burton to play the female lead in the fantasy romance Edward Scissorhands (1990), starring alongside Cher in the comedy-drama Mermaids (1990),…

scrubland, diverse assortment of vegetation types sharing the common physical characteristic of dominance by shrubs. A shrub is defined as a woody plant not exceeding 5 metres (16.4 feet) in height if it has a single main stem, or 8 metres if it is multistemmed. The world’s main areas of scrubland

Heathrow Airport, the largest and busiest airport in the United Kingdom and one of the busiest and most connected airports in the world. Opened in 1946 and located west of Central London, it provides service to more than 200 destinations in more than 80 countries. British Airways is the airport’s

heating, process and system of raising the temperature of an enclosed space for the primary purpose of ensuring the comfort of the occupants. By regulating the ambient temperature, heating also serves to maintain a building’s structural, mechanical, and electrical systems. The earliest method of

heat of reaction: …standard heats of formation and heats of combustion. The standard heat of formation is defined as the amount of heat absorbed or evolved at 25° C (77° F ) and at one atmosphere pressure when one mole of a compound is formed from its constituent elements, each substance being in…

HVAC, mechanical system used to control the temperature, humidity, and movement of air throughout a building or other indoor space. HVAC systems are used extensively in homes and businesses for comfort as well as safety from extreme weather or the effects of poor air circulation. They are also

Niles, city, Trumbull county, northeastern Ohio, U.S. It lies along the Mahoning River, about midway between Youngstown and Warren, and is a part of the Mahoning industrial complex. Ruben Harmon, the first white settler (1797), and others discovered deposits of coal, iron ore, and limestone there.

Olympic Games: St. Moritz, Switzerland, 1948: John Heaton (U.S.) won his second consecutive silver medal in the event, 20 years after winning his first medal at age 19. In the ski jump Birger Ruud, a two-time gold medalist, returned as coach of the Norwegian squad. Faced with poor weather conditions, however,…

heatstroke, condition caused by continuous exposure to high temperature and humidity for several hours. The term sunstroke refers to the same disorder when exposure to direct sunlight is the main cause of the condition. The primary feature of heatstroke is an extreme and uncontrolled elevation of

heat wave, period of prolonged abnormally high surface temperatures relative to those normally expected. Heat waves may span several days to several weeks and are significant causes of weather-related mortality, affecting developed and developing countries alike. Globally, the increasing frequency

helmet: …of metal increased until entire helmets were fashioned of iron, still following the same form. About the year 1200 the helm, or heaume, emerged. It was a flat-topped cylinder that was put on over the skullcap just before an engagement; experience soon dictated rounded contours that would cause blows to…

ship: Ship motions in response to the sea: … (rotation about a transverse axis), heave (vertical motion), and surge (longitudinal motion superimposed on the steady propulsive motion). All six are unwanted except in the special circumstance where yaw is necessary in changing course.

heaven, in many religions, the abode of God or the gods, as well as of angels, deified humans, the blessed dead, and other celestial beings. It is often conceived as an expanse that overarches the earth, stretching overhead like a canopy, dome, or vault and encompassing the sky and upper

history of film: European cinema: A film such as Heaven (2002), cowritten by the Polish filmmaker Krzysztof Kieślowski, with Tom Tykwer from Germany as director, set in Italy and spoken in Italian and English by American and Australian lead actors, seemed the rule rather than the exception. Another example is provided by the German-born…

12 Contemporary Black Authors You Must Read: James McBride: …2023 McBride earned raves for The Heaven & Earth Grocery Store. Part murder mystery, part historical fiction, the novel follows the friendships and divisions among the Jewish and Black residents of Pottstown, Pennsylvania, in the 1920s and ’30s.

Oliver Stone: InHeaven & Earth (1993), Stone approached the Vietnam War and its aftermath from the perspective of a young Vietnamese woman.

Warren Beatty: Even more successful was Heaven Can Wait (1978), a showcase vehicle for Beatty’s comedic talents. For this film, Beatty was nominated for Academy Awards in four separate categories (best actor, picture [producer], writing, and direction), an unprecedented achievement in Hollywood history and an achievement he was to repeat with…

Ernst Lubitsch: Films of the 1940s: Heaven Can Wait (1943), Lubitsch’s first film under a new producer-director contract with Twentieth Century-Fox, was a bittersweet period comedy in which a ladies’ man (Don Ameche) reviews a lifetime of romantic malfeasance for a skeptical Satan (Laird Cregar) as he awaits admittance to hell.…

John Huston: Films of the 1950s of John Huston: Heaven Knows, Mr. Allison (1957), a much quieter affair, starred Robert Mitchum and Deborah Kerr as a marine and a nun stranded on a Pacific island during World War II. Kerr received an Academy Award nomination for best actress, and Huston’s and John Lee Mahin’s…

Frank Herbert: … (1966), The Santaroga Barrier (1968), The Heaven Makers (1968), The God Makers (1972), and The Dosadi Experiment (1977).

Heaven’s Gate, film by director Michael Cimino that was released in 1980 and is, according to many critics, one of the worst films ever made. Hollywood’s film studios felt expansive during the 1970s. Relatively young directors such as Steven Spielberg, George Lucas and Francis Ford Coppola could

Heaven’s Gate, religious group founded in the United States on a belief in unidentified flying objects. Under a variety of names over the years, including Human Individual Metamorphosis, Bo and Peep, and Total Overcomers Anonymous, the group advocated extreme self-renunciation to the point of

California laurel, (Umbellularia californica), aromatic evergreen tree of the laurel family (Lauraceae). It occurs on the Pacific coast of North America from Oregon to California and grows about 15 to 25 metres (50 to 80 feet) tall. A handsome tree, it is often grown in gardens and along avenues.

Kingdom of God, in Christianity, the spiritual realm over which God reigns as king, or the fulfillment on Earth of God’s will. The phrase occurs frequently in the New Testament, primarily used by Jesus Christ in the first three Gospels. It is generally considered to be the central theme of Jesus’

tianming, in Chinese Confucian thought, the notion that heaven (tian) conferred directly upon an emperor, the son of heaven (tianzi), the right to rule. The doctrine had its beginnings in the early Zhou dynasty (c. 1046–256 bce). The continuation of the mandate was believed to be conditioned by the

tian: …as Son of Heaven (tianzi), and their authority was believed to emanate from tian. Beginning in the Zhou dynasty, sovereignty was explained by the concept of the mandate of heaven (tianming). This was a grant of authority that depended not on divine right but on virtue. Indeed, this authority…

tree of heaven, (Ailanthus altissima), rapid-growing tree, in the family Simaroubaceae, native to China but widely naturalized elsewhere. It has been planted as a yard and street tree in urban centres, because of its resistance to pollution, freedom from insects and disease, and ability to grow in

Ipomoea: Major species: Heavenly blue morning glory (I. violacea)—a twining perennial vine, usually cultivated as a garden annual—bears clusters of blue to purplish, sometimes white, flowers, 12 cm (4.7 inches) across, among heart-shaped leaves. It is native to tropical America. This vine bears seeds containing the alkaloids d-lysergic…

Carl Becker: …one of his best-known books, The Heavenly City of the Eighteenth Century Philosophers (1932), Becker not only examined the ideas of the Philosophes, such as their belief in progress and human perfectibility, but also stressed their intellectual fervour and their success in bridging traditional Christianity and Enlightenment secularism. During World…

Peter Jackson: …to a real-life incident for Heavenly Creatures (1994), about two teenage girls who kill one girl’s mother; the film starred Kate Winslet in her first major role. Its screenplay garnered Academy Award nominations for Jackson and Frances Walsh, his partner. The mock documentary Forgotten Silver (1995) and the ghost story…

Wendi: …a female servant, one called Tian Long (Heavenly Deaf One), the other Di Ya (Earthly Mute). The names suggest that Wendi must turn a deaf ear to those who inquire about the secrets of literature, for such a topic necessarily leaves one speechless.

Beijing: Public and commercial buildings: …contains three large halls, the Palace of Heavenly Purity (Qianqinggong), the Hall of Union (Jiaotaidian), and the Palace of Earthly Tranquillity (Kunninggong).

Dievs: Dievs has two sons (Dieva dēli in Latvian; Dievo sūneliai in Lithuanian), who are known as the Heavenly Twins and the morning and evening stars. Like their Greek (Dioscuri) and Vedic (Aśvins, or Nāsatyas) counterparts, Dieva dēli are skilled horsemen. They associate with Saules meita, the daughter of the…

Alison Lurie: …books for children, such as The Heavenly Zoo: Legends and Tales of the Stars (1979), Clever Gretchen and Other Forgotten Folktales (1980), and Fabulous Beasts (1981), as well as works about children’s literature. Her nonfiction works include Don’t Tell the Grown-Ups: Subversive Children’s Literature (1990). In addition, she coedited Classics…

Father Divine: …the first of his “Heavens,” the residential hotels where his teachings were practiced and where his followers could obtain food, shelter, and job opportunites, as well as spiritual and physical healing.

Kang Youwei: …reflections, completing his last book, The Heavens, in which he blended astronomy with his own metaphysical musing, a year before his death at Qingdao in 1927.

heaves, chronic disorder of the lungs of horses and cows, characterized by difficult breathing and wheezy cough. The symptoms are worsened by vigorous exercise, sudden weather changes, and overfeeding. Heaves resulting from bronchitis may be associated with the feeding of dusty or moldy hay. In

John Mayer: Mayer’s next studio release, Heavier Things (2003), topped the Billboard album chart and featured the hit “Daughters,” which was honoured with two Grammy Awards, including song of the year.

aviation: …the development and operation of heavier-than-air aircraft. The term military aviation refers to the development and use of military aircraft, while the term civil aviation refers to all nonmilitary aviation, such as air transportation provided by airlines or the carrying of cargo by commercial aircraft.

Mercury: Character of the surface: …occupy intercrater areas on the heavily cratered highlands of the Moon. There are also some sparsely cratered regions called smooth plains, many of which surround the most prominent impact structure on Mercury, the immense impact basin known as Caloris, only half of which was in sunlight during the Mariner 10…

Ghana: Economy of Ghana: …Bank and International Monetary Fund’s Heavily Indebted Poor Country program in 2002 and the total debt forgiveness plan agreed upon by the Group of Eight country leaders in Gleneagles, Scotland, in 2005, but by 2015 Ghana was suffering from a high debt burden again.

E region, ionospheric region that generally extends from an altitude of 90 km (60 miles) to about 160 km (100 miles). As in the D region (70–90 km), the ionization is primarily molecular—i.e., resulting from the splitting of neutral molecules—oxygen (O2) and nitrogen (N2)—into electrons and

Oliver Heaviside was a physicist who predicted the existence of the ionosphere, an electrically conductive layer in the upper atmosphere that reflects radio waves. In 1870 he became a telegrapher, but increasing deafness forced him to retire in 1874. He then devoted himself to investigations of

aerospace industry: Commercial heavy aircraft: The need for large-scale air transportation has been central to commercial aircraft manufacturing. As one of the world’s most vital industries, airlines are key to many aspects of the world economy, from international business and tourism to routine movement of people and goods…

tactics: The power of the defense: …only by tremendous concentrations of heavy artillery. Directed by forward observers and from balloons and aircraft overlooking the battlefield, artillery fired high explosive, gas, or—ideally, since the two called for different and even contradictory responses—a combination of both. The number of rounds fired could run into the millions; even so,…

tactics: Light and heavy cavalry: The next development following chariots was cavalry, which took two forms. From Mongolia to Persia and Anatolia—and, later, on the North American plains as well—nomadic peoples fought principally with missile weapons, especially the bow in its short, composite variety. Equipped with only light…

coal mining: Slurry pipelines: So-called heavy coal slurries or slurry fuels consist of 65 to 75 percent coal, with the remainder being water, methanol, or oil. Unlike traditional slurry—which is transported by pipeline to the user, who separates the water from the coal before burning—slurry fuels can be fired directly into boilers.

liquid: Equilibrium properties: …vapour pressure is called the heavy component.

Milky Way Galaxy: Principal population types: …considerably lower abundances of the heavy elements—by amounts ranging from a factor of 5 or 10 up to a factor of several hundred. The total abundance of heavy elements, Z, for typical Population I stars is 0.04 (given in terms of the mass percent for all elements with atomic weights…

tunnels and underground excavations: Heavy ground: The miner’s term for very weak or high geostress ground that causes repeated failures and replacement of support is heavy ground. Ingenuity, patience, and large increases of time and funds are invariably required to deal with it. Special techniques have generally been evolved…

history of Europe: Technological innovations: …greater striking force, and the draft horse, now shod with iron horseshoes that protected the hooves from the damp clay soils of northern Europe. The draft horse was faster and more efficient than the ox, the traditional beast of burden. The invention of the new horse collar in the 10th…

deuterium, isotope of hydrogen with a nucleus consisting of one proton and one neutron, which is double the mass of the nucleus of ordinary hydrogen (one proton). Deuterium has an atomic weight of 2.014. It is a stable atomic species found in natural hydrogen compounds to the extent of about 0.0156

industry: Secondary industry: Large-scale industry generally requires heavy capital investment in plants and machinery, serves a large and diverse market including other manufacturing industries, has a complex industrial organization and frequently a skilled specialized labour force, and generates a large volume of output. Examples would include petroleum refining,…

tactics: Light and heavy cavalry: …troops such as light and heavy infantry. The function of these cataphracts (from the Greek word for “armour”) was not to engage in long-distance combat but to launch massed shock action, first against the enemy cataphracts and then, having gained the field, against the enemy foot. The fact that ancient…

heavy ion, in nuclear physics, any particle with one or more units of electric charge and a mass exceeding that of the helium-4 nucleus (alpha particle). Special types of accelerators are capable of producing fairly intense, high-energy beams of heavy ions, which are used in basic research, as in

copernicium: In 1996 scientists at the Institute for Heavy Ion Research (Gesellschaft für Schwerionenforschung [GSI]) in Darmstadt, Ger., announced the production of atoms of copernicium from fusing zinc-70 with lead-208. The atoms of copernicium had an atomic weight of 277 and decayed after 0.24 millisecond by emission of an alpha particle…

machine gun: …War II the term “heavy machine gun” designated a water-cooled machine gun that was belt-fed, handled by a special squad of several soldiers, and mounted on a tripod. Since 1945 the term has designated an automatic weapon firing ammunition larger than that used in ordinary combat rifles; the most…

nervous system disease: Toxic effects of drugs, metals, and poisons: Heavy metals (e.g., arsenic, lead, thallium, gold, manganese, and mercury), synthetic chemicals (e.g., organophosphates, gasoline, and toluene), alcohols (especially ethyl and methyl alcohol), ionizing radiation, and many drugs can all be toxic to the nervous system. In addition, water overload can cause seizures, and oxygen,…

heavy metal, genre of rock music that includes a group of related styles that are intense, virtuosic, and powerful. Driven by the aggressive sounds of the distorted electric guitar, heavy metal is arguably the most commercially successful genre of rock music. Although the origin of the term heavy

Heavy Metal, Canadian animated science-fiction anthology film directed by Gerald Potterton and released in 1981. The film features stories that originally appeared in Heavy Metal magazine, as well as tales conceived specifically for the film. Aimed at an adult audience, Heavy Metal was hailed as an

heavy oil and tar sand, crude oils below 20° on the American Petroleum Institute (API) gravity scale that require mining or thermal recovery. Although the lighter conventional crudes are often waterflooded to enhance recovery, this method is essentially ineffective for heavy crudes between 20° and

radiation measurement: Interactions of heavy charged particles: The term heavy charged particle refers to those energetic particles whose mass is one atomic mass unit or greater. This category includes alpha particles, together with protons, deuterons, fission fragments, and other energetic heavy particles often produced in accelerators. These particles carry…

rapid transit, system of railways, usually electric, that is used for local transit in a metropolitan area. A rapid transit line may run underground (subway), above street level (elevated transit line), or at street level. Rapid transit is distinguished from other forms of mass transit by its

fish processing: Curing: In heavy or hard-cure salting, an additional step is taken in which warm air is forced over the surface of the fish until the water content is reduced to about 20 percent and the salt content is increased to approximately 30 percent. Most dry-salted fish products are consumed…

Anatoly Rybakov: …II in Tyazhyoly pesok (1979; Heavy Sand), an epic novel that brought him an international audience. With the arrival of Premier Mikhail Gorbachev’s policy of glasnost, Rybakov was allowed to publish Deti Arbata (1987; Children of the Arbat), much of which had been suppressed for more than two decades. The…

barite, the most common barium mineral, barium sulfate (BaSO4). Barite occurs in hydrothermal ore veins (particularly those containing lead and silver), in sedimentary rocks such as limestone, in clay deposits formed by the weathering of limestone, in marine deposits, and in cavities in igneous