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Cumberlandite
Cumberlandite is a type of igneous rock. It is the state rock of the U.S. state of Rhode Island. It is only found in large concentrations on a lot in Blackstone Valley, Cumberland, and in traces scattered throughout the Narragansett Bay watershed. Due to its high amounts of iron, it is slightly magnetic. Background The rocks were discovered by settlers hundreds of years ago, and were initially deemed valuable for the manufacture of cannon and farm tools in the 18th and 19th centuries. The rock also contains a relatively high level of titanium, also valuable for the manufacture of tools. Colonists tried to make cannon from the rock during the Revolutionary War, but the cannon cracked because of the weakness of the iron. Cumberlandite weathers to a brownish black with white crystals. This is strikingly different from the weathered look of other rocks in Rhode Island's glacial deposits. It is also much denser than the granites and metamorphic rocks that are common in these deposi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumberlandite
Cumberlandite is a type of igneous rock. It is the state rock of the U.S. state of Rhode Island. It is only found in large concentrations on a lot in Blackstone Valley, Cumberland, and in traces scattered throughout the Narragansett Bay watershed. Due to its high amounts of iron, it is slightly magnetic. Background The rocks were discovered by settlers hundreds of years ago, and were initially deemed valuable for the manufacture of cannon and farm tools in the 18th and 19th centuries. The rock also contains a relatively high level of titanium, also valuable for the manufacture of tools. Colonists tried to make cannon from the rock during the Revolutionary War, but the cannon cracked because of the weakness of the iron. Cumberlandite weathers to a brownish black with white crystals. This is strikingly different from the weathered look of other rocks in Rhode Island's glacial deposits. It is also much denser than the granites and metamorphic rocks that are common in these deposi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumberlandite Museum Of Natural History RI
Cumberlandite is a type of igneous rock. It is the state rock of the U.S. state of Rhode Island. It is only found in large concentrations on a lot in Blackstone Valley, Cumberland, and in traces scattered throughout the Narragansett Bay watershed. Due to its high amounts of iron, it is slightly magnetic. Background The rocks were discovered by settlers hundreds of years ago, and were initially deemed valuable for the manufacture of cannon and farm tools in the 18th and 19th centuries. The rock also contains a relatively high level of titanium, also valuable for the manufacture of tools. Colonists tried to make cannon from the rock during the Revolutionary War, but the cannon cracked because of the weakness of the iron. Cumberlandite weathers to a brownish black with white crystals. This is strikingly different from the weathered look of other rocks in Rhode Island's glacial deposits. It is also much denser than the granites and metamorphic rocks that are common in these deposi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rhode Island
Rhode Island (, like ''road'') is a U.S. state, state in the New England region of the Northeastern United States. It is the List of U.S. states by area, smallest U.S. state by area and the List of states and territories of the United States by population, seventh-least populous, with slightly fewer than 1.1 million residents 2020 United States census, as of 2020, but it is the List of U.S. states by population density, second-most densely populated after New Jersey. It takes its name from Aquidneck Island, the eponymous island, though most of its land area is on the mainland. Rhode Island borders Connecticut to the west; Massachusetts to the north and east; and the Atlantic Ocean to the south via Rhode Island Sound and Block Island Sound. It also shares a small maritime border with New York (state), New York. Providence, Rhode Island, Providence is its capital and most populous city. Native Americans lived around Narragansett Bay for thousands of years before English settler ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cumberland, Rhode Island
Cumberland is the northeasternmost town in Providence County, Rhode Island, United States, first settled in 1635 and incorporated in 1746. The population was 36,405 at the 2020 census, making it the seventh-largest municipality and the largest town in the state. History Cumberland was originally settled as part of Wrentham, Massachusetts, which was purchased from the local Indigenous Americans by the Plymouth Colony. It was later transferred to Rhode Island as part of a long-running boundary dispute. The town was named in honor of Prince William, Duke of Cumberland. William Blackstone (also spelled William Blaxton in colonial times) was the first European to settle and live in Cumberland. (He was also the first European to have settled in Boston, but left when he and the newly arrived Puritans disagreed about religion.) He preached his brand of tolerant Christianity under an oak tree that became an inspiration to Christians worldwide. He lived on a farm in the Lonsdale are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Igneous Rock
Igneous rock (derived from the Latin word ''ignis'' meaning fire), or magmatic rock, is one of the three main The three types of rocks, rock types, the others being Sedimentary rock, sedimentary and metamorphic rock, metamorphic. Igneous rock is formed through the cooling and solidification of magma or lava. The magma can be derived from Partial melting, partial melts of existing rocks in either a Terrestrial planet, planet's mantle (geology), mantle or crust (geology), crust. Typically, the melting is caused by one or more of three processes: an increase in temperature, a decrease in pressure, or a change in composition. Solidification into rock occurs either below the surface as intrusive rocks or on the surface as extrusive (geology), extrusive rocks. Igneous rock may form with crystallization to form granular, crystalline rocks, or without crystallization to form Volcanic glass, natural glasses. Igneous rocks occur in a wide range of geological settings: shields, platforms ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Matrix (geology)
The matrix or groundmass of a rock is the finer-grained mass of material in which larger grains, crystals, or clasts are embedded. The matrix of an igneous rock consists of finer-grained, often microscopic, crystals in which larger crystals, called phenocrysts, are embedded. This porphyritic texture is indicative of multi-stage cooling of magma. For example, porphyritic andesite will have large phenocrysts of plagioclase in a fine-grained matrix. Also in South Africa, diamonds are often mined from a matrix of weathered clay-like rock (kimberlite) called "yellow ground". The matrix of sedimentary rocks is finer-grained sedimentary material, such as clay or silt, in which larger grains or clasts are embedded. It is also used to describe the rock material in which a fossil is embedded. Cementation All sediments are at first in an incoherent condition (e.g. sands, clays and gravels, beds of shells), and they may remain in this state for an indefinite period. Millions of years have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plutonic Rocks
Intrusive rock is formed when magma penetrates existing rock, crystallizes, and solidifies underground to form '' intrusions'', such as batholiths, dikes, sills, laccoliths, and volcanic necks.Intrusive RocksIntrusive rocks accessdate: March 27, 2017.Igneous intrusive rocks, accessdate: March 27, 2017.Britannica.comintrusive rock , geology , Britannica.com accessdate: March 27, 2017. Intrusion is one of the two ways igneous rock can form. The other is extrusion, such as a volcanic eruption or similar event. An intrusion is any body of intrusive igneous rock, formed from magma that cools and solidifies within the crust of the planet. In contrast, an ''extrusion'' consists of extrusive rock, formed above the surface of the crust. Some geologists use the term plutonic rock synonymously with intrusive rock, but other geologists subdivide intrusive rock, by crystal size, into coarse-grained plutonic rock (typically formed deeper in the Earth's crust in batholiths or stocks) a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Proterozoic
The Neoproterozoic Era is the unit of geologic time from 1 billion to 538.8 million years ago. It is the last era of the Precambrian Supereon and the Proterozoic Eon; it is subdivided into the Tonian, Cryogenian, and Ediacaran periods. It is preceded by the Mesoproterozoic Era and succeeded by the Paleozoic Era of the Phanerozoic Eon. The most severe glaciation known in the geologic record occurred during the Cryogenian, when ice sheets may have reached the equator and formed a "Snowball Earth". The earliest fossils of complex multicellular life are found in the Ediacaran Period. These organisms make up the Ediacaran biota, including the oldest definitive animals in the fossil record. According to Rino and co-workers, the sum of the continental crust formed in the Pan-African orogeny and the Grenville orogeny makes the Neoproterozoic the period of Earth's history that has produced most continental crust. Geology At the onset of the Neoproterozoic the supercontinent Rodinia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamination (geology)
In geology, lamination () is a small-scale sequence of fine layers (laminae; singular: lamina) that occurs in sedimentary rocks. Laminae are normally smaller and less pronounced than bedding. Lamination is often regarded as planar structures one centimetre or less in thickness, whereas bedding layers are greater than one centimetre. However, structures from several millimetres to many centimetres have been described as laminae. A single sedimentary rock can have both laminae and beds. Description Lamination consists of small differences in the type of sediment that occur throughout the rock. They are caused by cyclic changes in the supply of sediment. These changes can occur in grain size, clay percentage, microfossil content, organic material content or mineral content and often result in pronounced differences in colour between the laminae. Weathering can make the differences even more clear. Lamination can occur as parallel structures (parallel lamination) or in different set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spinel
Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , which means ''spine'' in reference to its pointed crystals. Properties Spinel crystallizes in the isometric system; common crystal forms are octahedra, usually twinned. It has no true cleavage, but shows an octahedral parting and a conchoidal fracture. Its hardness is 8, its specific gravity is 3.5–4.1, and it is transparent to opaque with a vitreous to dull luster. It may be colorless, but is usually various shades of red, lavender, blue, green, brown, black, or yellow. Some spinels are among the most famous gemstones; among them are the Black Prince's Ruby and the "Timur ruby" in the British Crown Jewels, and the "Côte de Bretagne", formerly from the French Crown jewels. The Samarian Spinel is the largest known spinel in the world, weighing . The transparent red spinels were called spinel-rubies or b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hercynite
Hercynite is a spinel mineral with the formula FeAl2O4. It occurs in high-grade metamorphosed iron rich argillaceous sediments as well as in mafic and ultramafic igneous rocks. Due to its hardness it also is found in placers. It was first described in 1847 and its name originates from the Latin name for the Harz, Silva Hercynia, where the species was first found. Hercynite is a spinel of regular symmetry and normal cation distribution, but some disorder occurs in its structure. It consists of ferrous (Fe2+) ions and aluminium ions (Al3+), however some ferric ions (Fe3+) may be located in the structure of hercynite. Melting point The melting point (or, rarely, liquefaction point) of a substance is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depen ... of this mineral is inbetween . References Iron minerals Aluminium minerals Spinel group Cubic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
