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Spurrite
Spurrite is a white, yellow or light blue mineral with monoclinic crystals. Its chemical formula is Ca5( Si O4)2 CO3. Spurrite is generally formed in contact metamorphism zones as mafic magmas are intruded into carbonate rocks.Smith, J.V. (1960) "The Crystal structure of Spurrite, Ca5(SiO4)2CO3". ''Acta. Cryst.'' 13, 454 Spurrite's space group is P 2/a. It is biaxial with a birefringence of 0.0390–0.0400, giving second order red interference colors when viewed under crossed polarizers in a petrographic microscope. The calcium is in six-fold coordination with the oxygen, the silicon is in a four-fold coordination with the oxygen and the carbon is in two-fold coordination. One unique characteristic of spurrite is that it actually abides by two twin laws. Polysynthetic twinning can occur along its (001) and another type of twinning can occur parallel to its optical axes. Discovery and occurrence Spurrite was first described in 1908 for an occurrence in the Terneras Mine, V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Josiah Edward Spurr
Josiah Edward Spurr (1870–1950) was an American geologist, explorer, and author. Born in Gloucester, Massachusetts, he was considered something of a failure as a youth, unsuited for the family fishing business, since on a voyage he invariably became seasick. Since he could not be a productive fisherman like his brothers, his parents decided he might as well go to college. After working his way through Harvard, he began his career with the Minnesota Geological Survey, making the first-ever geological map of the great Mesabi iron range in Minnesota. J. E. Spurr led two expeditions of historic importance in Alaska for the United States Geological Survey in 1896 and 1898, made without the benefit of telephones, airplanes, the internal combustion engine, or electrical appliances. In 1896 he led the first expedition to map and chart the interior of Alaska, exploring the Yukon Territory, where gold had been discovered. In 1898 Spurr went down the length of the Kuskokwim River, naming ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesosilicate
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 a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petrographic Microscope
A petrographic microscope is a type of optical microscope used in petrology and optical mineralogy to identify rocks and minerals in thin sections. The microscope is used in optical mineralogy and petrography, a branch of petrology which focuses on detailed descriptions of rocks. The method is called "polarized light microscopy" (PLM). __TOC__ Description Depending on the grade of observation required, petrological microscopes are derived from conventional brightfield microscopes of similar basic capabilities by: * Adding a Nicol prism polarizer filter to the light path beneath the sample slide * Replacing the normal stage with a circular rotating stage (typically graduated with vernier scales for reading orientations to better than 1 degree of arc) * Adding a second rotatable and removable Nicol prism filter, called the analyzer, to the light path between objective and eyepiece * Adding a phase telescope, also known as a Bertrand lens, which allows the viewer to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbonate Minerals
Carbonate minerals are those minerals containing the carbonate ion, . Carbonate divisions Anhydrous carbonates *Calcite group: trigonal **Calcite CaCO3 **Gaspéite (Ni,Mg,Fe2+)CO3 **Magnesite MgCO3 **Otavite CdCO3 **Rhodochrosite MnCO3 **Siderite FeCO3 **Smithsonite ZnCO3 **Spherocobaltite CoCO3 *Aragonite group: orthorhombic **Aragonite CaCO3 **Cerussite PbCO3 **Strontianite SrCO3 **Witherite BaCO3 **Rutherfordine UO2CO3 **Natrite Na2CO3 Anhydrous carbonates with compound formulas *Dolomite group: trigonal **Ankerite CaFe(CO3)2 **Dolomite (mineral), Dolomite CaMg(CO3)2 **Huntite Mg3Ca(CO3)4 **Minrecordite CaZn(CO3)2 **Barytocalcite BaCa(CO3)2 Carbonates with hydroxyl or halogen *Carbonate with hydroxide: monoclinic **Azurite Cu3(CO3)2(OH)2 **Hydrocerussite Pb3(CO3)2(OH)2 **Malachite Cu2CO3(OH)2 **Rosasite (Cu,Zn)2CO3(OH)2 **Phosgenite Pb2(CO3)Cl2 **Hydrozincite Zn5(CO3)2(OH)6 **Aurichalcite (Zn,Cu)5(CO3)2(OH)6 Hydrated carbonates *Hydromagnesite Mg5(CO3)4(OH)2.4H2O *Ikaite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nesosilicates
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 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portland Cement
Portland cement is the most common type of cement in general use around the world as a basic ingredient of concrete, mortar, stucco, and non-specialty grout. It was developed from other types of hydraulic lime in England in the early 19th century by Joseph Aspdin, and is usually made from limestone. It is a fine powder, produced by heating limestone and clay minerals in a kiln to form clinker, grinding the clinker, and adding 2 to 3 percent of gypsum. Several types of portland cement are available. The most common, called ordinary portland cement (OPC), is grey, but white Portland cement is also available. Its name is derived from its resemblance to Portland stone which was quarried on the Isle of Portland in Dorset, England. It was named by Joseph Aspdin who obtained a patent for it in 1824. His son William Aspdin is regarded as the inventor of "modern" portland cement due to his developments in the 1840s. The low cost and widespread availability of the limestone, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis And Clark County, Montana
Lewis and Clark County is a county located in the U.S. state of Montana. As of the 2020 census, the population was 70,973. Its county seat is Helena, the state capital. The numerical designation for Lewis and Clark County (used in the issuance of the state's license plates) is 5. The county was established on June 2, 1865 as one of the nine original counties of the Territory of Montana named Edgerton County in honor of Sidney Edgerton, first Governor of the Territory of Montana, and was renamed Lewis and Clark County on March 1, 1868 in honor of explorers Meriwether Lewis and William Clark. Lewis and Clark County is part of the Helena, Montana Micropolitan Statistical Area. Geography According to the United States Census Bureau, the county has a total area of , of which is land and (1.1%) is water. Major highways * * * * * * * * Adjacent counties * Teton County - north * Cascade County - east * Meagher County - east * Broadwater County - southeast * Jeff ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Little Belt Mountains
The Little Belt Mountains are a section of the Rocky Mountains in the U.S. state of Montana. Situated mainly in the Lewis and Clark National Forest, the mountains are used for logging and recreation for the residents of Great Falls, Montana. Showdown is a ski area located within the mountains located off US Highway 89 which splits the mountains in half connecting White Sulphur Springs and Belt, MT. The highest point in the Little Belt Range is Big Baldy Mountain at . The Little Belts have been mined for silver since the 1880s, and for sapphire since 1896. The sapphires, called Yogo sapphires as they are mined near Yogo Creek, occur in a formation long and across. The mountains are named for a butte in the range, Belt Butte, itself named for a band of white rock which encircles it. The Showdown Ski Area holds the state's record for snowfall, of snow in one winter. The mountain range of gently rolling peaks and expansive conifer forests contains two large roadless areas. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luna County, New Mexico
Luna County is a county located in the U.S. state of New Mexico. As of the 2010 census, the population was 25,095. Its county seat is Deming. This county abuts the Mexican border. Luna County comprises the Deming, NM Micropolitan Statistical Area. History Luna County was formed from parts of Grant County and Doña Ana County by the New Mexico Legislature on March 16, 1901. It was named for Solomon Luna, a politician who advocated for independence of the county, following a strong rivalry between the cities of Deming and Silver City, both of which were at the time in Grant County. Before dawn on March 16, 1916, Mexican revolutionary Pancho Villa led several hundred of his rebel soldiers across the Mexican border into the southern county village of Columbus. The invaders raided and burned much of the town, causing many residents to flee to the desert. Although the raid completely surprised everyone in the town, it also awakened 350 United States Army soldiers at Camp Furl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riverside County, California
Riverside County is a county located in the southern portion of the U.S. state of California. As of the 2020 census, the population was 2,418,185, making it the fourth-most populous county in California and the 10th-most populous in the United States. The name was derived from the city of Riverside, which is the county seat. Riverside County is included in the Riverside- San Bernardino-Ontario Metropolitan Statistical Area, also known as the Inland Empire. The county is also included in the Los Angeles-Long Beach Combined Statistical Area. Roughly rectangular, Riverside County covers in Southern California, spanning from the greater Los Angeles area to the Arizona border. Geographically, the county is mostly desert in the central and eastern portions, but has a Mediterranean climate in the western portion. Most of Joshua Tree National Park is located in the county. The resort cities of Palm Springs, Palm Desert, Indian Wells, La Quinta, Rancho Mirage, and Desert Hot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatemala, Belize, and the Caribbean Sea; and to the east by the Gulf of Mexico. Mexico covers ,Mexico ''''. . making it the world's 13th-largest country by are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Durango
Durango (), officially named Estado Libre y Soberano de Durango ( en, Free and Sovereign State of Durango; Tepehuán: ''Korian''; Nahuatl: ''Tepēhuahcān''), is one of the 31 states which make up the 32 Federal Entities of Mexico, situated in the northwest of the country. With a population of 1,832,650, the 8th lowest of Mexico's states, Durango has Mexico's second-lowest population density, after Baja California Sur. The capital city, Victoria de Durango, is named after the first President of Mexico, Guadalupe Victoria. Geography General information With , Durango accounts for about 6.3% of the entire territory of Mexico. It is the fourth largest state lying at the extreme northwest of the Central Mexican Plateau, where it meets the Sierra Madre Occidental—the highest peaks in the state. The state has an average elevation of 1,775 meters above sea level, with a mean elevation of 1,750 m in the Valleys region and 2,450 m in the Sierra region. The city of Durango is on t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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