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Benitoite
Benitoite () is a rare blue barium titanium cyclosilicate, found in hydrothermally altered serpentinite. It forms in low temperature, high pressure environments typical of subduction zones at convergent plate boundaries. Benitoite fluoresces under short wave ultraviolet light, appearing bright blue to bluish white in color. The more rarely seen clear to white benitoite crystals fluoresce red under long-wave UV light. It was discovered in 1907 by prospector James M. Couch in the San Benito Mountains roughly halfway between San Francisco and Los Angeles. Due to its similar color, Couch originally believed it to be sapphire, a variety of corundum. In 1909, a sample was sent to the University of California, Berkeley, where mineralogist Dr. George D. Louderback realized it was a previously unknown mineral. Corundum (sapphire) has a defined Mohs hardness of 9, while benitoite is much softer. He named it ''benitoite'' for its occurrence near the headwaters of the San Benito River in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bentonite
Bentonite () is an absorbent swelling clay consisting mostly of montmorillonite (a type of smectite) which can either be Na-montmorillonite or Ca-montmorillonite. Na-montmorillonite has a considerably greater swelling capacity than Ca-montmorillonite. Bentonite usually forms from the weathering of volcanic ash in seawater, or by hydrothermal circulation through the porosity of volcanic ash beds, which converts ( devitrification) the volcanic glass (obsidian, rhyolite, dacite) present in the ash into clay minerals. In the mineral alteration process, a large fraction (up to 40-50 wt.%) of amorphous silica is dissolved and leached away, leaving the bentonite deposit in place. Bentonite beds are white or pale blue or green (traces of reduced ) in fresh exposures, turning to a cream color and then yellow, red, or brown (traces of oxidized ) as the exposure is weathered further. As a swelling clay, bentonite has the ability to absorb large quantities of water, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silicate Mineral
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous earth. General structure A silicate mineral is generally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Louderback
George Davis Louderback (April 6, 1874 – January 27, 1957) was an American geologist, known for identifying and describing benitoite and joaquinite. Biography Louderback was born in San Francisco, and received an A.B. from the University of California, Berkeley in 1896, followed by a Ph.D. in 1899. He married Clara Augusta Henry on October 3, 1899. He was a teaching assistant in mineralogy at UC Berkeley in 1897–1900 and then taught at the University of Nevada in 1900–1906. At UC Berkeley's department of geology, Louderback became an assistant professor in 1906, an associate professor in 1907, and a full professor in 1917. In Nevada, Louderback studied the geological structure of the Great Basin, especially of the Basin ranges, and Nevada's gypsum deposits. He did research on the Mesozoic formations of southern Oregon, the relation of radioactivity to vulcanism, the glaucophane of the Pacific Coast Ranges, and the stratigraphy of Mount Diablo. He also studied the effects ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barium
Barium is a chemical element with the symbol Ba and atomic number 56. It is the fifth element in group 2 and is a soft, silvery alkaline earth metal. Because of its high chemical reactivity, barium is never found in nature as a free element. The most common minerals of barium are baryte (barium sulfate, BaSO4) and witherite ( barium carbonate, BaCO3). The name ''barium'' originates from the alchemical derivative "baryta", from Greek (), meaning 'heavy'. ''Baric'' is the adjectival form of barium. Barium was identified as a new element in 1774, but not reduced to a metal until 1808 with the advent of electrolysis. Barium has few industrial applications. Historically, it was used as a getter for vacuum tubes and in oxide form as the emissive coating on indirectly heated cathodes. It is a component of YBCO ( high-temperature superconductors) and electroceramics, and is added to steel and cast iron to reduce the size of carbon grains within the microstructure. Barium compou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclosilicate
Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth's crust. In mineralogy, silica (silicon dioxide, ) is usually considered a silicate mineral. Silica is found in nature as the mineral quartz, and its polymorphs. On Earth, a wide variety of silicate minerals occur in an even wider range of combinations as a result of the processes that have been forming and re-working the crust for billions of years. These processes include partial melting, crystallization, fractionation, metamorphism, weathering, and diagenesis. Living organisms also contribute to this geologic cycle. For example, a type of plankton known as diatoms construct their exoskeletons ("frustules") from silica extracted from seawater. The frustules of dead diatoms are a major constituent of deep ocean sediment, and of diatomaceous earth. General structure A silicate mineral is general ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexagonal Crystal System
In crystallography, the hexagonal crystal family is one of the six crystal families, which includes two crystal systems (hexagonal and trigonal) and two lattice systems (hexagonal and rhombohedral). While commonly confused, the trigonal crystal system and the rhombohedral lattice system are not equivalent (see section crystal systems below). In particular, there are crystals that have trigonal symmetry but belong to the hexagonal lattice (such as α- quartz). The hexagonal crystal family consists of the 12 point groups such that at least one of their space groups has the hexagonal lattice as underlying lattice, and is the union of the hexagonal crystal system and the trigonal crystal system. There are 52 space groups associated with it, which are exactly those whose Bravais lattice is either hexagonal or rhombohedral. __TOC__ Lattice systems The hexagonal crystal family consists of two lattice systems: hexagonal and rhombohedral. Each lattice system consists of one Brav ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Japan
Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north toward the East China Sea, Philippine Sea, and Taiwan in the south. Japan is a part of the Ring of Fire, and spans an archipelago of 6852 islands covering ; the five main islands are Hokkaido, Honshu (the "mainland"), Shikoku, Kyushu, and Okinawa. Tokyo is the nation's capital and largest city, followed by Yokohama, Osaka, Nagoya, Sapporo, Fukuoka, Kobe, and Kyoto. Japan is the eleventh most populous country in the world, as well as one of the most densely populated and urbanized. About three-fourths of the country's terrain is mountainous, concentrating its population of 123.2 million on narrow coastal plains. Japan is divided into 47 administrative prefectures and eight traditional regions. The Greater Tokyo Ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkansas
Arkansas ( ) is a landlocked state in the South Central United States. It is bordered by Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, and Texas and Oklahoma to the west. Its name is from the Osage language, a Dhegiha Siouan language, and referred to their relatives, the Quapaw people. The state's diverse geography ranges from the mountainous regions of the Ozark and Ouachita Mountains, which make up the U.S. Interior Highlands, to the densely forested land in the south known as the Arkansas Timberlands, to the eastern lowlands along the Mississippi River and the Arkansas Delta. Arkansas is the 29th largest by area and the 34th most populous state, with a population of just over 3 million at the 2020 census. The capital and most populous city is Little Rock, in the central part of the state, a hub for transportation, business, culture, and government. The northwestern corner of the state, including the Fayetteville ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montana
Montana () is a U.S. state, state in the Mountain states, Mountain West List of regions of the United States#Census Bureau-designated regions and divisions, division of the Western United States. It is bordered by Idaho to the west, North Dakota and South Dakota to the east, Wyoming to the south, and the Provinces and territories of Canada, Canadian provinces of Alberta, British Columbia, and Saskatchewan to the north. It is the List of U.S. states and territories by area, fourth-largest state by area, the List of U.S. states and territories by population, eighth-least populous state, and the List of U.S. states and territories by population density, third-least densely populated state. Its state capital is Helena, Montana, Helena. The western half of Montana contains numerous mountain ranges, while the eastern half is characterized by western prairie terrain and badlands, with smaller mountain ranges found throughout the state. Montana has no official nickname but several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
California
California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the most populated subnational entity in North America and the 34th most populous in the world. The Greater Los Angeles area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions respectively, with the former having more than 18.7million residents and the latter having over 9.6million. Sacramento is the state's capital, while Los Angeles is the most populous city in the state and the second most populous city in the country. San Francisco is the second most densely populated major city in the country. Los Angeles County is the country's most populous, while San Bernardino County is the largest county by area in the country. California borders Oregon to the north, Nevada and Arizona to the ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Los Angeles
Los Angeles ( ; es, Los Ángeles, link=no , ), often referred to by its initials L.A., is the largest city in the state of California and the second most populous city in the United States after New York City, as well as one of the world's most populous megacities. Los Angeles is the commercial, financial, and cultural center of Southern California. With a population of roughly 3.9 million residents within the city limits , Los Angeles is known for its Mediterranean climate, ethnic and cultural diversity, being the home of the Hollywood film industry, and its sprawling metropolitan area. The city of Los Angeles lies in a basin in Southern California adjacent to the Pacific Ocean in the west and extending through the Santa Monica Mountains and north into the San Fernando Valley, with the city bordering the San Gabriel Valley to it's east. It covers about , and is the county seat of Los Angeles County, which is the most populous county in the United States with an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
San Benito County
San Benito County (; ''San Benito'', Spanish for "St. Benedict"), officially the County of San Benito, is a county located in the Coast Range Mountains of the U.S. state of California. As of the 2020 census, the population was 64,209. The county seat is Hollister. San Benito County is included in the San Jose- Sunnyvale- Santa Clara, CA Metropolitan Statistical Area, which is also included in the San Jose-San Francisco-Oakland, CA Combined Statistical Area. El Camino Real passes through the county and includes one mission in San Juan Bautista. History Before the arrival of the first European settlers, the San Benito County area was inhabited by the Mutsun sub-group of the Ohlone Native Americans. In 1772 Father Juan Crespí conducted a brief expedition into the area and named a small river which he found in honor of San Benito de Nursia ( Saint Benedict), the patron saint of monasticism. The county was later named after the San Benito Valley, the valley surrounding this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
