Is chert a sedimentary rock

Feb 13, 2023 · Chert breccia. Rock Type: Sedimentary – A poorly sorted and immature detrital (clastic) sedimentary rock made up of angular rock fragments that are gravel sized or larger (2mm or more). Click on image to see enlarged photo.

Is chert a sedimentary rock. Chert, another commonly found chemical sedimentary rock, is usually produced from silica (SiO 2) precipitated from groundwater. Silica is highly insoluble on the surface of Earth, which is why quartz is so resistant to chemical weathering.

Chert is the name for a widespread type of sedimentary rock that is made of silica (silicon dioxide or SiO 2 ). The most familiar silica mineral is quartz in microscopic or even invisible crystals; that is, microcrystalline or cryptocrystalline quartz. Learn more about how it is made and find out what it is made of. Chert Ingredients

1 Oct 2019 ... White chert veins, irrespective of their thickness, have diffuse and irregular (Figure 7) or sharp. (Figure 8) contacts with surrounding rocks; ...Sedimentary rocks are formed from preexisting rock through the combined processes of weathering, transportation, deposition, compacting and cementation. The entire series of processes is known as lithification, and the weathering portion of...Chert is a sedimentary rock composed mostly of the mineral chalcedony—cryptocrystalline silica in crystals of submicroscopic size. This type of sedimentary rock can form in parts of the deep sea where the tiny shells of siliceous organisms are concentrated, or elsewhere where underground fluids replace sediments with silica. ...It is a hard, extremely dense, dull to semiglossy sedimentary rock (microcrystalline to cryptocrystalline quartz). Chert consists predominantly of silica, with occasional impurities such as calcite, iron oxides, clay minerals, and the organic remains of marine organisms made of silica, amounting to about 10 percent.What is Chert? Chert is a sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO 2). It occurs as nodules, concretionary masses, and as layered deposits. Chert breaks with a conchoidal fracture, often producing very sharp edges. Question 4 Which of the following best describes intrusive rocks? a. do not undergo crystallization b. are often vesicular c. form at the Earth's surface Selected: d. are generally coarse-grained This answer is correct. Correct! Intrusive rocks form underground, where the crystals are larger and do not have "air" pockets or vesicles, so they tend to be more …Dec 20, 2022 · The scientists analyzed circa 550 million-year-old chemical sedimentary rocks, known as cherts, which form from seawater and the remains of silica-secreting organisms. Credit: Michael Tatzel

ADVERTISEMENTS: Here is a list of twelve important sedimentary rocks: 1. Breccia 2. Conglomerates 3. Sandstones 4. Shale 5. Limestones 6. Dolomite 7. Coals 8. Iron Ores 9. Gypsum 11. Rock Salt 12. Flint and Chert. 1. Breccia: It is a mechanically formed sedimentary rock classed as Rudite. It consists of angular fragments of heterogeneous …(See Figure 1.) Chert is a crystalline sedimentary rock rich in silicon dioxide (silica). ... View in full-text ...True. __ is a hard, compact, very fine-grained sedimentary rock composed entirely of silica. Chert. _____ forms from limestone when the calcium in calcite is partially replaced by magnesium. Dolomite. Sediments are unconsolidated, which means the grains are separate and unattached to one another. True.Chert is a sedimentary rock made up of microcrystalline. It can be found in the form of nodules, masses, and layered deposits. Coal is an organic ...Chert is a fine-grained sedimentary rock mainly composed of quartz. It can be white, gray, yellow, or brown in color. In Wisconsin, it is prominent in mounds capped by chert in the southwestern part of the state that are roughly 425 to 475 million years old.Sedimentary Rocks and the Rock Cycle - South Carolina Department of Natural ResourcesLearn about the formation, classification, and characteristics of sedimentary rocks, one of the three major rock types in the Earth's crust. This PDF presentation also explains how sedimentary rocks are involved in the rock cycle, the continuous process …The meaning of CHERT is a rock resembling flint and consisting essentially ... chert, a sedimentary rock. — Mark Barna, Discover Magazine, 20 June 2018. The ...The term ‘chert’ ideally refers to fine-grained siliceous (micro/cryptocrystalline) mineral and is also often used for rock with such siliceous mineral aggregate of chemical, biochemical, and organic origin. Petrologically, inorganic non-sedimentary origin or even volcanic derivatives formed by devitrification of metastable felsic volcanic glass can also be included within chert. A new ...

All the quarries in Jackson County have chert, while you can also find the sedimentary rock along with flint specimens in stream banks, road cuts, and quarries around Washington County. Chipley is another area where plenty of limestone exposures are present, among road cuts and other environments where you can commonly find chert.sedimentary basins are formed by a process called. all of the above. the study of sedimentary rocks helps geoscientists determine __________. a. ancient ocean environments. b. former plate tectonic events. c. history of climate change. d. all of the above. Study with Quizlet and memorize flashcards containing terms like chemical …Some examples of sedimentary rocks. Chalk is a fine-grained limestone, usually formed by compacted microscopic animals called foraminifera. Chert is a fine-grained hard sedimentary rock composed of microscopic silica grains, and has a flat fracture. Flint is a variety of chert (mostly of upper Cretaceous age) that has a conchoidal fracture.A variety of silica that lacks external evidence of crystal form. It is chalcedony (SiO 2) in a nodular or lens-like habit, formed in a sedimentary environment.Florida is similarly abundant in chert rocks and varieties like Missouri. Here, you can find red fossiliferous chert in streams and creek beds at Cottondale. All the quarries in Jackson County have chert, while you can also find the sedimentary rock along with flint specimens in stream banks, road cuts, and quarries around Washington County.

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-A sedimentary rock made of these sediment grains would be conglomerate . The image below consists of chert sediment grains and includes a scale bar showing measurement in centimeters. Use this image to answer the following. Address the following regarding the sample above: ...If the material makes up a sedimentary rock unit that can be traced from one geographic location to another, geologists are likely to call the material "chert". Some of these cherts can be thick enough and laterally extensive enough to serve as oil and gas reservoirs over a broad geographic area. Chert is a chemical sedimentary rock that seems like it could be considered organic at times. It can contain remains of what is called siliceous ooze, or very small organic ocean life remains. Chert is very fine grained and will …Chert is the name for a widespread type of sedimentary rock that is made of silica (silicon dioxide or SiO 2 ). The most familiar silica mineral is quartz in microscopic or even invisible crystals; that is, microcrystalline or cryptocrystalline quartz. Learn more about how it is made and find out what it is made of. Chert IngredientsChert is the name for a widespread type of sedimentary rock that is made of silica (silicon dioxide or SiO 2 ). The most familiar silica mineral is quartz in microscopic or even invisible crystals; that is, microcrystalline or cryptocrystalline quartz. Learn more about how it is made and find out what it is made of. Chert Ingredients

Chert. Chert is a chemical sedimentary rock composed of microcrystalline quartz. In its gray form, it is called flint. It makes sparks when struck against steel. Chert (Photograph by Parvinder Sethi) <Flint is a hard, tough chemical or biochemical sedimentary rock that breaks with a conchoidal fracture. It is a form of microcrystalline quartz that is typically called "chert" by geologists. Flint often forms as nodules in sedimentary rocks such as chalk and marine limestones. The nodules can be dispersed randomly throughout the rock unit but ...20 Oct 2009 ... ... chert, early diagenesis, eastern Precordillera, Lower Ordovician. INTRODUCTION. Chert is a hard, dense or compact sedimentary rock, con-.Chert is also the name given to hard sedimentary rock composed of fine quartz crystals. The rock seen in Figure 7.75 is an example. The rock seen in Figure 7.75 is an example. Chert (the rock) is usually of biological origin, being the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor.Includes fault slivers of Devonian rocks (Kleweno and Jeffords, 1961), Coffee Creek Formation of Mississippian age, Spotted Ridge Formation of Pennsylvanian age (Merriam and Berthiaume, 1943; Mamay and Read, 1956), and Paleozoic sedimentary and metamorphosed sedimentary and volcanic rocks, including sericite schist, amphibolite, and hornblende ...7.4.7: Chert. Chert is a fine-grained (microcrystalline) variety of quartz. It is also the name given to rock composed primarily of fine-grained quartz. So, the name is used in two ways. Chert (the silica mineral kind) may be massive or layered. It is often in nodules or concretions in limestone. Some chert forms by recrystallization of ...Sedimentary rock - Silica, Clastic, Chemical: Those siliceous rocks composed of an exceptionally high amount of crystalline siliceous material, mainly the mineral quartz (especially microcrystalline quartz and fibrous chalcedony) and amorphous opal, are most commonly known as chert. A wide variety of rock names are applied to cherty rocks reflecting their colour (flint is dark chert; jasper is ... Shale is a fine-grained sedimentary rock which is formed by the compaction of silt and clay-size mineral particles. Chert is a hard, dark, opaque sedimentary rock which is composed of silica with an amorphous fine-grained texture. These rocks are composed of many distinct minerals. The process of formation of rocks is different for various rocks.Conglomerate is a clastic sedimentary rock made up of rounded clasts that are greater than two millimeters in diameter. The spaces between the clasts are generally filled with sand- and clay-size particles. The rock is bound together by a cement that is usually composed of calcite or quartz.

Limestone is a sedimentary rock primarily composed of calcium carbonate (CaCO3) in the form of mineral calcite or aragonite.It is one of the most common and widely distributed rocks on Earth, with a wide range of uses in various industries and natural settings. Limestone forms through the accumulation and compaction of marine …

Conglomerate is a clastic sedimentary rock made up of rounded clasts that are greater than two millimeters in diameter. The spaces between the clasts are generally filled with sand- and clay-size particles. The rock is bound together by a cement that is usually composed of calcite or quartz. Chert is a hard, fine-grained sedimentary rock that is often gray, black, or brown in color. It is composed of microcrystalline quartz, and is similar in composition to flint. Chert is often found in layers within other types of sedimentary rock, and was commonly used by ancient peoples to make tools and weapons due to its hardness and ability ...Chert is normally considered to be a sedimentary rock. Picasso Chert from Burro Creek, AZ, collected by Arizona State University Geology Professor and Author Stan Celestian. But there are now multiple variations being scientifically studied and shown worldwide that contain multiple minerals and patterns. Most chert rocks contain some …Nov 1, 2016 · Despite appearance, all forms of chert have the same basic composition. It is a hard, brittle sedimentary rock composed of finely crystalline quartz and its chemical base is silica (SiO 2). The presence of impurities gives the stone colors other than white. Shale is a rock composed mainly of clay-size mineral grains. These tiny grains are usually clay minerals such as illite, kaolinite, and smectite. Shale usually contains other clay-size mineral particles such as quartz, chert, and feldspar. Other constituents might include organic particles, carbonate minerals, iron oxide minerals, sulfide ...Rocks and minerals can be easily identified once you know what to look for. There are three different types of rocks: Igneous, Metamorphic and Sedimentary. Minerals must meet several requirements, including being naturally occurring and ino...Chert is a sedimentary rock rich in silica. Franciscan chert is formed from the tiny silica shells (0.5-1 mm) of marine plankton called Radiolaria. Radiolarian chert forms where two conditions are met. First, a deep, open ocean setting is required where there is little continental mud or carbonate sediment to dilute the “rain” of dead ...Sedimentary Rock Classification Diagrams Click the image for the full-size version. ThoughtCo/Andrew Alden. This diagram is used like the QFL diagram, but it is designed for provenance studies of sandstones that contain a lot of chert or polycrystalline quartz (quartzite) grains. Qm is monocrystalline quartz, F is feldspar, and Lt is total lithics.

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While chert is a clearly defined rock type, it can still be difficult to know whether a rock you've found is chert, especially when you consider there are so ...Chert (/ ˈ tʃ ɜːr t /) is a hard, fine-grained sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO 2). Chert is characteristically of biological origin, but may also occur inorganically as a chemical precipitate or a diagenetic replacement, as in petrified wood . Chert is a hard and compact sedimentary rock, consisting dominantly of very small quartz crystals. It is a common rock type which occurs mostly in carbonate rocks either in nodular form or in layers (bedded chert). Flint on the coast at Stevns Klint in Denmark.Sedimentary rock 'chert' records cooling of the Earth over billions of years. by University of Göttingen. The scientists analyzed circa 550 million-year-old chemical sedimentary rocks, known as ...Sedimentary rocks are formed from pre-existing rocks or pieces of once-living organisms. They form from deposits that accumulate on the Earth’s surface. Sedimentary rocks often have distinctive layering or bedding. Many of the picturesque views of the desert southwest show mesas and arches made of layered sedimentary rock.Chert can be a chemical sedimentary rock, often forming as beds within limestone (Figure 9.13), or as irregular lenses or blobs (nodules). It can also be biochemical. Some tiny marine organisms (e.g., diatoms and radiolaria) make their tests from silica. When they die their tiny shells settle slowly to the bottom of the lake or ocean, where ...Includes fault slivers of Devonian rocks (Kleweno and Jeffords, 1961), Coffee Creek Formation of Mississippian age, Spotted Ridge Formation of Pennsylvanian age (Merriam and Berthiaume, 1943; Mamay and Read, 1956), and Paleozoic sedimentary and metamorphosed sedimentary and volcanic rocks, including sericite schist, amphibolite, and hornblende ... The most common chemical sedimentary rock, by far, is limestone. Others include chert , banded iron formation, and a variety of rocks that form when bodies of water evaporate. Biological processes are important in the formation of some chemical sedimentary rocks, especially limestone and chert.Chert nodule. Nodules of chert are rounded to elongated silica-rich lumps that occur within sequences of limestones (commonly chalk and calcilutites). They originate from the diagenesis of an original silica-rich carbonatic ooze, containing remains of organisms like radiolarians or diatoms, which produce shells made of silica.Nov 28, 2020 · The Formation of Chert. Chert will form in carbonate type rocks, whish is a type of sedimentary rock, as nodules or larger masses. As the sediment that can make up greensand, chalk, dolomite, and limestone get buried deep within the earth over time, these pockets of chert will form as well in the immense pressure and heat. Two major types of iron-rich sedimentary rocks are recognized: (1) iron formation, or banded iron formation (BIF)—regionally extensive, locally thick sequences composed of alternating thin (millimetre to centimetre thick) layers of mainly crystalline-textured iron-rich minerals and chert—and (2) ironstone—noncherty, essentially clastic ... ….

Recognizing Minerals in Sedimentary Rocks. How to Identify Sedimentary Rocks. A. If grains or crystals are visible without a hand lens and: 1. The rock scratches glass, use Table 4.4. 2. The rock won’t scratch glass, use Table 4.5. B. If grains or crystals are not visible, or barely visible with a hand lens: 1. The rock is a shale or mudstone ...Chert is a fine-grained sedimentary rock composed of quartz (SiO2) that is microcrystalline or cryptocrystalline quartz. It is usually organic rock but also occur inorganically as a chemical precipitate or a diagenetic replacement. It occurs as nodules, concretionary masses, and as layered deposits.Bone to Stone: Building Fossils - Building fossils starts after the organic parts of an animal break down, leaving the bones behind. Learn more about the process of building fossils. Advertisement Most of the dinosaur skeletons you see in m...Chert is also the name given to hard sedimentary rock composed of fine quartz crystals. The rock seen in Figure 7.75 is an example. The rock seen in Figure 7.75 is an example. Chert (the rock) is usually of biological origin, being the petrified remains of siliceous ooze, the biogenic sediment that covers large areas of the deep ocean floor.20 Oct 2009 ... ... chert, early diagenesis, eastern Precordillera, Lower Ordovician. INTRODUCTION. Chert is a hard, dense or compact sedimentary rock, con-.chert and flint, very fine-grained quartz ( q.v. ), a silica mineral with minor impurities. Several varieties are included under the general term chert: jasper, chalcedony, agate ( qq.v. ), flint, porcelanite, and novaculite. Flint is gray to black and nearly opaque (translucent brown in thin splinters) because of included carbonaceous matter.Sedimentary rocks are formed from preexisting rock through the combined processes of weathering, transportation, deposition, compacting and cementation. The entire series of processes is known as lithification, and the weathering portion of...Sedimentary Rocks and the Rock Cycle - South Carolina Department of Natural ResourcesLearn about the formation, classification, and characteristics of sedimentary rocks, one of the three major rock types in the Earth's crust. This PDF presentation also explains how sedimentary rocks are involved in the rock cycle, the continuous process of changing rocks from one type to another. Explore the ...Cryptocrystalline. Cryptocrystalline is a rock texture made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically [1] in thin section by transmitted polarized light. Among the sedimentary rocks, chert and flint are cryptocrystalline. Carbonado, a form of diamond, is also cryptocrystalline. Is chert a sedimentary rock, Geologists use _____ rocks to determine past environments of deposition on Earth's surface. These types of rocks preserve a variety of characteristics that might suggest temperature, elevation, geographic location, and changes in climate. sedimentary. Match the environmental depositional shift to its correct description., Chert, a type of sedimentary rock ... This print showcases the raw beauty of Chert, a mesmerizing type of sedimentary rock. Against a clean white background, the ..., Chert and flint are microcrystalline varieties of quartz. Their quartz crystals are so tiny that chert and flint fracture more like glass than quartz crystals. A skilled person can chip chert and flint pieces into arrow heads, spear points, and other tools. The only difference between chert and flint is color: flint is black or nearly black and ..., 4. Concrete Production. Sedimentary rock used as aggregate in concrete production to withstand pressure. Fig. 5: Limestone aggregate for concrete production. 5. Pavement and Road Construction. Sandstone and limestone have been used for the construction of pavement stone and road stone., Examples of chemical sedimentary rocks include rock salt, trona and chert. Organic sedimentary rocks form when organic material (dead plants, animal shells, etc.) are compressed and cemented over time to form rock. Examples of organic sedimentary rocks include coal, some limestone and fossiliferous rocks (CGS, n.d.b; USGS, 2014b). , Sedimentary rocks - rocks formed by the accumulation and consolidation of sediments (surficial processes). I. Sediments - material that is deposited by wind, water or ice; material that is precipitated from seawater; or deposits of organic origin. A. Major Components - (clastics, biogenic and chemical precipitates)., A number of classification schemes have been proposed to further subdivide conglomerates and breccias. One scheme is purely descriptive, partitioning these coarse clastic sedimentary rocks on the basis of grain size (e.g., boulder breccia versus cobble conglomerate) or composition or both (chert pebble breccia versus limestone cobble conglomerate)., Chert is a chemical sedimentary rock that seems like it could be considered organic at times. It can contain remains of what is called siliceous ooze, or very small organic ocean life remains. Chert is very fine grained and will …, Sedimentary rocks are one of three main types of rocks, along with igneous and metamorphic. They are formed on or near the Earth’s surface from the compression of ocean sediments or other …, Chert is a microcrystalline or cryptocrystalline sedimentary rock made up of silica (silicon dioxide or SiO2). A popular silica mineral is quartz., Limestone is a sedimentary rock composed primarily of calcite, a calcium carbonate mineral with a chemical composition of CaCO 3. It usually forms in clear, calm, warm, shallow marine waters. Limestone is usually a biological sedimentary rock, forming from the accumulation of shell, coral, algal, fecal, and other organic debris., A. Chemical sedimentary rocks are crystalline in texture. B. Gypsum and halite are evaporite minerals. C. Both chert and limestone may have either chemical or biochemical origin. D. Dolostone and limestone are polymorphs—they have the same chemical composition. D. Dolostone and limestone are polymorphs—they have the same chemical …, Sedimentary rock - Clastic, Chemical, Organic: There are many different systems of classifying sandstones, but the most commonly used schemes incorporate both texture (the presence and amount of either interstitial matrix—i.e., clasts with diameters finer than 0.03 millimetre—or chemical cement) and mineralogy (the relative amount of quartz and the …, Includes fault slivers of Devonian rocks (Kleweno and Jeffords, 1961), Coffee Creek Formation of Mississippian age, Spotted Ridge Formation of Pennsylvanian age (Merriam and Berthiaume, 1943; Mamay and Read, 1956), and Paleozoic sedimentary and metamorphosed sedimentary and volcanic rocks, including sericite schist, amphibolite, and hornblende ..., 7.4.7: Chert. Chert is a fine-grained (microcrystalline) variety of quartz. It is also the name given to rock composed primarily of fine-grained quartz. So, the name is used in two ways. Chert (the silica mineral kind) may be massive or layered. It is often in nodules or concretions in limestone. Some chert forms by recrystallization of ..., If the material makes up a sedimentary rock unit that can be traced from one geographic location to another, geologists are likely to call the material "chert". Some of these cherts can be thick enough and laterally extensive enough to serve as oil and gas reservoirs over a broad geographic area. , Volcanic fragments: Fragmentation of volcanic rocks releases phenocrysts and groundmass clasts to the depositional setting.The composition of groundmass varies with rock type but consists mostly of …, Chert, another commonly found chemical sedimentary rock, is usually produced from silica (SiO 2) precipitated from groundwater. Silica is highly insoluble on the surface of Earth, …, Gneiss (/ n aɪ s / NICE) is a common and widely distributed type of metamorphic rock.It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks.Gneiss forms at higher temperatures and pressures than schist.Gneiss nearly always shows a banded texture characterized by …, What is Chert? Chert is a sedimentary rock composed of microcrystalline or cryptocrystalline quartz, the mineral form of silicon dioxide (SiO 2). It occurs as nodules, concretionary masses, and as layered deposits. Chert breaks with a conchoidal fracture, often producing very sharp edges., Chert is a very hard sedimentary rock that is usually found in nodules in limestone. Chert is light gray to dark gray in color. It probably formed from the ..., calcareous nannoplankton. marginal marine sequence of siltstones (reddish layers at the cliff base) and (brown rocks above), , southwestern , U.S. Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name ... , calcareous nannoplankton. marginal marine sequence of siltstones (reddish layers at the cliff base) and (brown rocks above), , southwestern , U.S. Sedimentary rocks are types of rock that are formed by the accumulation or deposition of mineral or organic particles at Earth's surface, followed by cementation. Sedimentation is the collective name ... , A variety of silica that lacks external evidence of crystal form. It is chalcedony (SiO 2) in a nodular or lens-like habit, formed in a sedimentary environment., Rocks and minerals can be easily identified once you know what to look for. There are three different types of rocks: Igneous, Metamorphic and Sedimentary. Minerals must meet several requirements, including being naturally occurring and ino..., These types of sedimentary rocks usually occur in arid areas, like gypsum and salt deposits. Examples of chemical sedimentary rocks are chert, dolomites, flint, rock salt, iron ore, and some types of limestone. 2. Clastic. Clastic sedimentary rocks occur when there is a buildup of tiny pieces of broken rocks (clastic)., Feb 13, 2023 · Chert breccia. Rock Type: Sedimentary – A poorly sorted and immature detrital (clastic) sedimentary rock made up of angular rock fragments that are gravel sized or larger (2mm or more). Click on image to see enlarged photo. , A. Replacement chert forms when silica plankton shells are replaced by calcite, and biochemical chert forms from the accumulation of dolomite shells. B. Replacement chert forms when silica is removed from a rock and biochemical chert forms when the soft, organic tissue of organisms is fossilized., Flint is a hard, tough chemical or biochemical sedimentary rock that breaks with a conchoidal fracture. It is a form of microcrystalline quartz that is typically called "chert" by geologists. Flint often forms as nodules in sedimentary rocks such as chalk and marine limestones. The nodules can be dispersed randomly throughout the rock unit but ... , Chert is the name for a widespread type of sedimentary rock that is made of silica (silicon dioxide or SiO 2 ). The most familiar silica mineral is quartz in microscopic or even invisible crystals; that is, …, Sedimentary Rocks. Weathering processes break down rock into finer and finer material and such material is often transported and deposited as sediment. The processes of compaction and cementation of this sediment over a long period of time turn the sediment into rock. ... Chert: Nonclastic: Halite, NaCl: Rock salt: Nonclastic: gypsum, CaSO 4.2H ..., Chert is a biochemical sedimentary rock made from microcrystalline quartz. It is very hard – registering a 7 on the Mohs hardness scale, and displays conchoidal fracturing. Chert …, siliceous rock, any of a group of sedimentary rocks that consist largely or almost entirely of silicon dioxide (SiO 2), either as quartz or as amorphous silica and cristobalite; included are rocks that have formed as chemical precipitates and excluded are those of detrital or fragmental origin.. The most common siliceous rock is chert, which is a dense, …