Grossular
Grossular is a calcium-aluminium species of the garnet group of minerals. It has the chemical formula of Ca3Al23 but the calcium may, in part, be replaced by ferrous iron and the aluminium by ferric iron; the name grossular is derived from the botanical name for the gooseberry, grossularia, in reference to the green garnet of this composition, found in Siberia. Other shades include cinnamon brown and yellow. Grossular is a gemstone, its streak is brownish white In geological literature, grossular has been called grossularite. Since 1971, use of the term grossularite for the mineral has been discouraged by the International Mineralogical Association. Hessonite or "cinnamon stone" is a common variety of grossular with the general formula: Ca3Al2Si3O12; the name comes from the Ancient Greek: ἣσσων, meaning inferior. It has a characteristic red color, much like that of zircon, it was shown many years ago, by Sir Arthur Herbert Church, that many gemstones engraved gems, were hessonite. The difference is detected by the specific gravity, that of hessonite being 3.64 to 3.69, while that of zircon is about 4.6.
Hessonite has a similar hardness to that of quartz, while the hardness of most garnet species is nearer 7.5. Hessonite comes chiefly from Sri Lanka and India, where it is found in placer deposits, though its occurrence in its native matrix is not unknown, it is found in Brazil and California. Grossular is found in contact metamorphosed limestones with vesuvianite, diopside and wernerite. A sought after variety of gem garnet is the fine green Grossular garnet from Kenya and Tanzania called tsavorite; this garnet was discovered in the 1960s in the Tsavo area of Kenya, from which the gem takes its name. Viluite is a variety name of grossular, not a recognized mineral species, it is olive green though sometimes brownish or reddish, brought about by impurities in the crystal. Viluite is found associated with and is similar in appearance to vesuvianite, there is confusion in terminology as viluite has long been used as a synonym for wiluite, a sorosilicate of the vesuvianite group; this confusion in nomenclature dates back to James Dwight Dana.
It comes from the Vilyuy river area in Siberia. Grossular is known by many other names, some misnomers. Misnomers include South African jade, garnet jade, Transvaal jade, African jade. Vermont has grossular garnet as its state gemstone. Hydrogrossular Webmineral data Mineral Data Publishing
Geology
Geology is an earth science concerned with the solid Earth, the rocks of which it is composed, the processes by which they change over time. Geology can include the study of the solid features of any terrestrial planet or natural satellite such as Mars or the Moon. Modern geology overlaps all other earth sciences, including hydrology and the atmospheric sciences, so is treated as one major aspect of integrated earth system science and planetary science. Geology describes the structure of the Earth on and beneath its surface, the processes that have shaped that structure, it provides tools to determine the relative and absolute ages of rocks found in a given location, to describe the histories of those rocks. By combining these tools, geologists are able to chronicle the geological history of the Earth as a whole, to demonstrate the age of the Earth. Geology provides the primary evidence for plate tectonics, the evolutionary history of life, the Earth's past climates. Geologists use a wide variety of methods to understand the Earth's structure and evolution, including field work, rock description, geophysical techniques, chemical analysis, physical experiments, numerical modelling.
In practical terms, geology is important for mineral and hydrocarbon exploration and exploitation, evaluating water resources, understanding of natural hazards, the remediation of environmental problems, providing insights into past climate change. Geology is a major academic discipline, it plays an important role in geotechnical engineering; the majority of geological data comes from research on solid Earth materials. These fall into one of two categories: rock and unlithified material; the majority of research in geology is associated with the study of rock, as rock provides the primary record of the majority of the geologic history of the Earth. There are three major types of rock: igneous and metamorphic; the rock cycle illustrates the relationships among them. When a rock solidifies or crystallizes from melt, it is an igneous rock; this rock can be weathered and eroded redeposited and lithified into a sedimentary rock. It can be turned into a metamorphic rock by heat and pressure that change its mineral content, resulting in a characteristic fabric.
All three types may melt again, when this happens, new magma is formed, from which an igneous rock may once more solidify. To study all three types of rock, geologists evaluate the minerals; each mineral has distinct physical properties, there are many tests to determine each of them. The specimens can be tested for: Luster: Measurement of the amount of light reflected from the surface. Luster is broken into nonmetallic. Color: Minerals are grouped by their color. Diagnostic but impurities can change a mineral’s color. Streak: Performed by scratching the sample on a porcelain plate; the color of the streak can help name the mineral. Hardness: The resistance of a mineral to scratch. Breakage pattern: A mineral can either show fracture or cleavage, the former being breakage of uneven surfaces and the latter a breakage along spaced parallel planes. Specific gravity: the weight of a specific volume of a mineral. Effervescence: Involves dripping hydrochloric acid on the mineral to test for fizzing. Magnetism: Involves using a magnet to test for magnetism.
Taste: Minerals can have a distinctive taste, like halite. Smell: Minerals can have a distinctive odor. For example, sulfur smells like rotten eggs. Geologists study unlithified materials, which come from more recent deposits; these materials are superficial deposits. This study is known as Quaternary geology, after the Quaternary period of geologic history. However, unlithified material does not only include sediments. Magmas and lavas are the original unlithified source of all igneous rocks; the active flow of molten rock is studied in volcanology, igneous petrology aims to determine the history of igneous rocks from their final crystallization to their original molten source. In the 1960s, it was discovered that the Earth's lithosphere, which includes the crust and rigid uppermost portion of the upper mantle, is separated into tectonic plates that move across the plastically deforming, upper mantle, called the asthenosphere; this theory is supported by several types of observations, including seafloor spreading and the global distribution of mountain terrain and seismicity.
There is an intimate coupling between the movement of the plates on the surface and the convection of the mantle. Thus, oceanic plates and the adjoining mantle convection currents always move in the same direction – because the oceanic lithosphere is the rigid upper thermal boundary layer of the convecting mantle; this coupling between rigid plates moving on the surface of the Earth and the convecting mantle is called plate tectonics. The development of plate tectonics has provided a physical basis for many observations of the solid Earth. Long linear regions of geologic features are explained as plate boundaries. For example: Mid-ocean ridges, high regions on the seafloor where hydrothermal vents and volcanoes exist, are seen as divergent boundaries, where two plates move apart. Arcs of volcanoes and earthquakes are theorized as convergent boundaries, where one plate subducts, or moves, under another. Transform boundaries, such as the San Andreas Fault system, resulted in widespread powerful earthquakes.
Plate tectonics has provided a mechan
Sri Lanka
Sri Lanka the Democratic Socialist Republic of Sri Lanka, is an island country in South Asia, located in the Indian Ocean to the southwest of the Bay of Bengal and to the southeast of the Arabian Sea. The island is geographically separated from the Indian subcontinent by the Gulf of Mannar and the Palk Strait; the legislative capital, Sri Jayawardenepura Kotte, is a suburb of the commercial capital and largest city, Colombo. Sri Lanka's documented history spans 3,000 years, with evidence of pre-historic human settlements dating back to at least 125,000 years, it has a rich cultural heritage and the first known Buddhist writings of Sri Lanka, the Pāli Canon, date back to the Fourth Buddhist council in 29 BC. Its geographic location and deep harbours made it of great strategic importance from the time of the ancient Silk Road through to the modern Maritime Silk Road. Sri Lanka was known from the beginning of British colonial rule as Ceylon. A nationalist political movement arose in the country in the early 20th century to obtain political independence, granted in 1948.
Sri Lanka's recent history has been marred by a 26-year civil war, which decisively ended when the Sri Lanka Armed Forces defeated the Liberation Tigers of Tamil Eelam in 2009. The current constitution stipulates the political system as a republic and a unitary state governed by a semi-presidential system, it has had a long history of international engagement, as a founding member of the South Asian Association for Regional Cooperation, a member of the United Nations, the Commonwealth of Nations, the G77, the Non-Aligned Movement. Along with the Maldives, Sri Lanka is one of only two South Asian countries rated "high" on the Human Development Index, with its HDI rating and per capita income the highest among South Asian nations; the Sri Lankan constitution accords Buddhism the "foremost place", although it does not identify it as a state religion. Buddhism is given special privileges in the Sri Lankan constitution; the island is home to many cultures and ethnicities. The majority of the population is from the Sinhalese ethnicity, while a large minority of Tamils have played an influential role in the island's history.
Moors, Malays and the indigenous Vedda are established groups on the island. In antiquity, Sri Lanka was known to travellers by a variety of names. According to the Mahavamsa, the legendary Prince Vijaya named the land Tambapanni, because his followers' hands were reddened by the red soil of the area. In Hindu mythology, such as the Ramayana, the island was referred to as Lankā; the Tamil term Eelam, was used to designate the whole island in Sangam literature. The island was known under Chola rule as Mummudi Cholamandalam. Ancient Greek geographers called it Taprobanē from the word Tambapanni; the Persians and Arabs referred to it as Sarandīb from Cerentivu or Siṃhaladvīpaḥ. Ceilão, the name given to Sri Lanka by the Portuguese Empire when it arrived in 1505, was transliterated into English as Ceylon; as a British crown colony, the island was known as Ceylon. The country is now known in Sinhala in Tamil as Ilaṅkai. In 1972, its formal name was changed to "Free and Independent Republic of Sri Lanka".
In 1978 it was changed to the "Democratic Socialist Republic of Sri Lanka". As the name Ceylon still appears in the names of a number of organisations, the Sri Lankan government announced in 2011 a plan to rename all those over which it has authority; the pre-history of Sri Lanka goes back 125,000 years and even as far back as 500,000 years. The era spans the Palaeolithic and early Iron Ages. Among the Paleolithic human settlements discovered in Sri Lanka, which dates back to 37,000 BP, Batadombalena and Belilena are the most important. In these caves, archaeologists have found the remains of anatomically modern humans which they have named Balangoda Man, other evidence suggesting that they may have engaged in agriculture and kept domestic dogs for driving game. One of the first written references to the island is found in the Indian epic Ramayana, which provides details of a kingdom named Lanka, created by the divine sculptor Vishwakarma for Kubera, the Lord of Wealth, it is said that Kubera was overthrown by his demon stepbrother Ravana, the powerful emperor who built a mythical flying machine named Dandu Monara.
The modern city of Wariyapola is described as Ravana's airport. Early inhabitants of Sri Lanka were ancestors of the Vedda people, an indigenous people numbering 2,500 living in modern-day Sri Lanka; the 19th-century Irish historian James Emerson Tennent theorized that Galle, a city in southern Sri Lanka, was the ancient seaport of Tarshish from which King Solomon is said to have drawn ivory and other valuables. According to the Mahāvamsa, a chronicle written in Pāḷi, the original inhabitants of Sri Lanka are the Yakshas and Nagas. Ancient cemeteries that were used before 600 BC and other signs of advanced civilisation have been discovered in Sri Lanka. Sinhalese history traditionally starts in 543 BC with the arrival of Prince Vijaya, a semi-legendary prince who sailed with 700 followers to Sri Lanka, after being expelled from Vanga Kingdom (present-day Ben
Alaska
Alaska is a U. S. state in the northwest extremity of North America, just across the Bering Strait from Asia. The Canadian province of British Columbia and territory of Yukon border the state to the east and southeast, its most extreme western part is Attu Island, it has a maritime border with Russia to the west across the Bering Strait. To the north are the Chukchi and Beaufort seas—southern parts of the Arctic Ocean; the Pacific Ocean lies to southwest. It is the largest U. S. state by the seventh largest subnational division in the world. In addition, it is the most sparsely populated of the 50 United States. Half of Alaska's residents live within the Anchorage metropolitan area. Alaska's economy is dominated by the fishing, natural gas, oil industries, resources which it has in abundance. Military bases and tourism are a significant part of the economy; the United States purchased Alaska from the Russian Empire on March 30, 1867, for 7.2 million U. S. dollars at two cents per acre. The area went through several administrative changes before becoming organized as a territory on May 11, 1912.
It was admitted as the 49th state of the U. S. on January 3, 1959. The name "Alaska" was introduced in the Russian colonial period when it was used to refer to the Alaska Peninsula, it was derived from an Aleut-language idiom. It means object to which the action of the sea is directed. Alaska is the northernmost and westernmost state in the United States and has the most easterly longitude in the United States because the Aleutian Islands extend into the Eastern Hemisphere. Alaska is the only non-contiguous U. S. state on continental North America. It is technically part of the continental U. S. but is sometimes not included in colloquial use. S. called "the Lower 48". The capital city, Juneau, is situated on the mainland of the North American continent but is not connected by road to the rest of the North American highway system; the state is bordered by Yukon and British Columbia in Canada, to the east, the Gulf of Alaska and the Pacific Ocean to the south and southwest, the Bering Sea, Bering Strait, Chukchi Sea to the west and the Arctic Ocean to the north.
Alaska's territorial waters touch Russia's territorial waters in the Bering Strait, as the Russian Big Diomede Island and Alaskan Little Diomede Island are only 3 miles apart. Alaska has a longer coastline than all the other U. S. states combined. Alaska is the largest state in the United States by total area at 663,268 square miles, over twice the size of Texas, the next largest state. Alaska is larger than all but 18 sovereign countries. Counting territorial waters, Alaska is larger than the combined area of the next three largest states: Texas and Montana, it is larger than the combined area of the 22 smallest U. S. states. There are no defined borders demarcating the various regions of Alaska, but there are six accepted regions: The most populous region of Alaska, containing Anchorage, the Matanuska-Susitna Valley and the Kenai Peninsula. Rural unpopulated areas south of the Alaska Range and west of the Wrangell Mountains fall within the definition of South Central, as do the Prince William Sound area and the communities of Cordova and Valdez.
Referred to as the Panhandle or Inside Passage, this is the region of Alaska closest to the rest of the United States. As such, this was where most of the initial non-indigenous settlement occurred in the years following the Alaska Purchase; the region is dominated by the Alexander Archipelago as well as the Tongass National Forest, the largest national forest in the United States. It contains the state capital Juneau, the former capital Sitka, Ketchikan, at one time Alaska's largest city; the Alaska Marine Highway provides a vital surface transportation link throughout the area, as only three communities enjoy direct connections to the contiguous North American road system. Designated in 1963; the Interior is the largest region of Alaska. Fairbanks is the only large city in the region. Denali National Park and Preserve is located here. Denali is the highest mountain in North America. Southwest Alaska is a sparsely inhabited region stretching some 500 miles inland from the Bering Sea. Most of the population lives along the coast.
Kodiak Island is located in Southwest. The massive Yukon–Kuskokwim Delta, one of the largest river deltas in the world, is here. Portions of the Alaska Peninsula are considered part of Southwest, with the remaining portions included with the Aleutian Islands; the North Slope is tundra peppered with small villages. The area is known for its massive reserves of crude oil, contains both the National Petroleum Reserve–Alaska and the Prudhoe Bay Oil Field; the city of Utqiagvik known as Barrow, is the northernmost city in the United States and is located here. The Northwest Arctic area, anchored by Kotzebue and containing the Kobuk River valley, is regarded as being part of this region. However, the respective Inupiat of the No
Abrasive
An abrasive is a material a mineral, used to shape or finish a workpiece through rubbing which leads to part of the workpiece being worn away by friction. While finishing a material means polishing it to gain a smooth, reflective surface, the process can involve roughening as in satin, matte or beaded finishes. In short, the ceramics which are used to cut and polish other softer materials are known as abrasives. Abrasives are commonplace and are used extensively in a wide variety of industrial and technological applications; this gives rise to a large variation in the physical and chemical composition of abrasives as well as the shape of the abrasive. Some common uses for abrasives include grinding, buffing, cutting, sharpening and sanding. Files are not abrasives. However, diamond files are a form of coated abrasive. Abrasives rely upon a difference in hardness between the abrasive and the material being worked upon, the abrasive being the harder of the two substances. However, is not necessary as any two solid materials that rub against each other will tend to wear each other away.
Materials used as abrasives are either hard minerals or are synthetic stones, some of which may be chemically and physically identical to occurring minerals but which cannot be called minerals as they did not arise naturally. Diamond, a common abrasive, for instance occurs both and is industrially produced, as is corundum which occurs but, nowadays more manufactured from bauxite; however softer minerals like calcium carbonate are used as abrasives, such as "polishing agents" in toothpaste. These minerals are either crushed or are of a sufficiently small size to permit their use as an abrasive; these grains called grit, have rough edges terminating in points which will decrease the surface area in contact and increase the localised contact pressure. The abrasive and the material to be worked are brought into contact while in relative motion to each other. Force applied through the grains causes fragments of the worked material to break away, while smoothing the abrasive grain and/or causing the grain to work loose from the rest of the abrasive.
Some factors which will affect how a substance is abraded include: Difference in hardness between the two substances: a much harder abrasive will cut faster and deeper Grain size: larger grains will cut faster as they cut deeper Adhesion between grains, between grains and backing, between grains and matrix: determines how grains are lost from the abrasive and how soon fresh grains, if present, are exposed Contact force: more force will cause faster abrasion Loading: worn abrasive and cast off work material tends to fill spaces between abrasive grains so reducing cutting efficiency while increasing friction Use of lubricant/coolant/metalworking fluid: Can carry away swarf, transport heat, decrease friction, suspend worn work material and abrasives allowing for a finer finish, conduct stress to the workpiece. Abrasives may be classified as either synthetic; when discussing sharpening stones, natural stones have long been considered superior but advances in material technology are seeing this distinction become less distinct.
Many synthetic abrasives are identical to a natural mineral, differing only in that the synthetic mineral has been manufactured rather than mined. Impurities in the natural mineral may make it less effective; some occurring abrasives are: Calcite Emery Diamond dust Novaculite Pumice Iron oxide Sand Corundum Garnet Sandstone Tripoli Powdered feldspar StauroliteSome abrasive minerals occur but are sufficiently rare or sufficiently more difficult or costly to obtain such that a synthetic stone is used industrially. These and other artificial abrasives include: Borazon Ceramic Ceramic aluminium oxide Ceramic iron oxide Corundum Dry ice Glass powder Steel abrasive Silicon carbide Zirconia alumina Boron carbide Slags Abrasives are shaped for various purposes. Natural abrasives are sold as dressed stones in the form of a rectangular block. Both natural and synthetic abrasives are available in a wide variety of shapes coming as bonded or coated abrasives, including blocks, discs, sheets and loose grains.
A bonded abrasive is composed of an abrasive material contained within a matrix, although fine aluminium oxide abrasive may comprise sintered material. This matrix is called a binder and is a clay, a resin, a glass or a rubber; this mixture of binder and abrasive is typic
Crystal system
In crystallography, the terms crystal system, crystal family, lattice system each refer to one of several classes of space groups, point groups, or crystals. Informally, two crystals are in the same crystal system if they have similar symmetries, although there are many exceptions to this. Crystal systems, crystal families and lattice systems are similar but different, there is widespread confusion between them: in particular the trigonal crystal system is confused with the rhombohedral lattice system, the term "crystal system" is sometimes used to mean "lattice system" or "crystal family". Space groups and crystals are divided into seven crystal systems according to their point groups, into seven lattice systems according to their Bravais lattices. Five of the crystal systems are the same as five of the lattice systems, but the hexagonal and trigonal crystal systems differ from the hexagonal and rhombohedral lattice systems; the six crystal families are formed by combining the hexagonal and trigonal crystal systems into one hexagonal family, in order to eliminate this confusion.
A lattice system is a class of lattices with the same set of lattice point groups, which are subgroups of the arithmetic crystal classes. The 14 Bravais lattices are grouped into seven lattice systems: triclinic, orthorhombic, rhombohedral and cubic. In a crystal system, a set of point groups and their corresponding space groups are assigned to a lattice system. Of the 32 point groups that exist in three dimensions, most are assigned to only one lattice system, in which case both the crystal and lattice systems have the same name. However, five point groups are assigned to two lattice systems and hexagonal, because both exhibit threefold rotational symmetry; these point groups are assigned to the trigonal crystal system. In total there are seven crystal systems: triclinic, orthorhombic, trigonal and cubic. A crystal family is determined by lattices and point groups, it is formed by combining crystal systems which have space groups assigned to a common lattice system. In three dimensions, the crystal families and systems are identical, except the hexagonal and trigonal crystal systems, which are combined into one hexagonal crystal family.
In total there are six crystal families: triclinic, orthorhombic, tetragonal and cubic. Spaces with less than three dimensions have the same number of crystal systems, crystal families and lattice systems. In one-dimensional space, there is one crystal system. In 2D space, there are four crystal systems: oblique, rectangular and hexagonal; the relation between three-dimensional crystal families, crystal systems and lattice systems is shown in the following table: Note: there is no "trigonal" lattice system. To avoid confusion of terminology, the term "trigonal lattice" is not used; the 7 crystal systems consist of 32 crystal classes as shown in the following table: The point symmetry of a structure can be further described as follows. Consider the points that make up the structure, reflect them all through a single point, so that becomes; this is the'inverted structure'. If the original structure and inverted structure are identical the structure is centrosymmetric. Otherwise it is non-centrosymmetric.
Still in the non-centrosymmetric case, the inverted structure can in some cases be rotated to align with the original structure. This is a non-centrosymmetric achiral structure. If the inverted structure cannot be rotated to align with the original structure the structure is chiral or enantiomorphic and its symmetry group is enantiomorphic. A direction is called polar if its two directional senses are physically different. A symmetry direction of a crystal, polar is called a polar axis. Groups containing a polar axis are called polar. A polar crystal possesses a unique polar axis; some geometrical or physical property is different at the two ends of this axis: for example, there might develop a dielectric polarization as in pyroelectric crystals. A polar axis can occur only in non-centrosymmetric structures. There cannot be a mirror plane or twofold axis perpendicular to the polar axis, because they would make the two directions of the axis equivalent; the crystal structures of chiral biological molecules can only occur in the 65 enantiomorphic space groups.
The distribution of the 14 Bravais lattices into lattice systems and crystal families is given in the following table. In geometry and crystallography, a Bravais lattice is a category of translative symmetry groups in three directions; such symmetry groups consist of translations by vectors of the form R = n1a1 + n2a2 + n3a3,where n1, n2, n3 are integers and a1, a2, a3 are three non-coplanar vectors, called primitive vectors. These lattices are classified by the space group of the lattice itself, viewed as a collection of points, they represent the maximum symmetry. All crystalline materials must, by definition, fit into one of these arrangements. For convenience a Bravais lattice is depicted by a unit cell, a factor 1, 2, 3 or 4 larger than the primitive cell. Depending on the symmetry of a crystal or other pattern, the fundamental domain is again smaller, up to a factor 48; the Bravais lattices were studied by Moritz Ludwig Frankenheim in 1842, who found that there we
Connecticut
Connecticut is the southernmost state in the New England region of the United States. As of the 2010 Census, it has the highest per-capita income, Human Development Index, median household income in the United States, it is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, Long Island Sound to the south. Its capital is Hartford and its most populous city is Bridgeport, it is part of New England, although portions of it are grouped with New York and New Jersey as the Tri-state area. The state is named for the Connecticut River which bisects the state; the word "Connecticut" is derived from various anglicized spellings of an Algonquian word for "long tidal river". Connecticut's first European settlers were Dutchmen who established a small, short-lived settlement called Fort Hoop in Hartford at the confluence of the Park and Connecticut Rivers. Half of Connecticut was part of the Dutch colony New Netherland, which included much of the land between the Connecticut and Delaware Rivers, although the first major settlements were established in the 1630s by the English.
Thomas Hooker led a band of followers from the Massachusetts Bay Colony and founded the Connecticut Colony. The Connecticut and New Haven colonies established documents of Fundamental Orders, considered the first constitutions in America. In 1662, the three colonies were merged under a royal charter; this was one of the Thirteen Colonies. Connecticut is the third smallest state by area, the 29th most populous, the fourth most densely populated of the 50 states, it is known as the "Constitution State", the "Nutmeg State", the "Provisions State", the "Land of Steady Habits". It was influential in the development of the federal government of the United States; the Connecticut River, Thames River, ports along Long Island Sound have given Connecticut a strong maritime tradition which continues today. The state has a long history of hosting the financial services industry, including insurance companies in Hartford and hedge funds in Fairfield County. Landmarks and cities of Connecticut Connecticut is bordered on the south by Long Island Sound, on the west by New York, on the north by Massachusetts, on the east by Rhode Island.
The state capital and fourth largest city is Hartford, other major cities and towns include Bridgeport, New Haven, Waterbury, Danbury, New Britain and Bristol. Connecticut is larger than the country of Montenegro. There are 169 incorporated towns in Connecticut; the highest peak in Connecticut is Bear Mountain in Salisbury in the northwest corner of the state. The highest point is just east of where Connecticut and New York meet, on the southern slope of Mount Frissell, whose peak lies nearby in Massachusetts. At the opposite extreme, many of the coastal towns have areas that are less than 20 feet above sea level. Connecticut has a long maritime history and a reputation based on that history—yet the state has no direct oceanfront; the coast of Connecticut sits on Long Island Sound, an estuary. The state's access to the open Atlantic Ocean is both to the east; this situation provides many safe harbors from ocean storms, many transatlantic ships seek anchor inside Long Island Sound when tropical cyclones pass off the upper East Coast.
The Connecticut River cuts through the center of the state. The most populous metropolitan region centered within the state lies in the Connecticut River Valley. Despite Connecticut's small size, it features wide regional variations in its landscape. Connecticut's rural areas and small towns in the northeast and northwest corners of the state contrast with its industrial cities such as Stamford and New Haven, located along the coastal highways from the New York border to New London northward up the Connecticut River to Hartford. Many towns in northeastern and northwestern Connecticut center around a green, such as the Litchfield Green, Lebanon Green, Wethersfield Green. Near the green stand historical visual symbols of New England towns, such as a white church, a colonial meeting house, a colonial tavern or inn, several colonial houses, so on, establishing a scenic historical appearance maintained for both historic preservation and tourism. Many of the areas in southern and coastal Connecticut have been built up and rebuilt over the years, look less visually like traditional New England.
The northern boundary of the state with Massachusetts is marked by the Southwick Jog or Granby Notch, an 2.5 miles square detour into Connecticut. The origin of this anomaly is established in a long line of disputes and temporary agreements which were concluded in 1804, when southern Southwick's residents sought to leave Massachusetts, the town was split in half; the southwestern border of Connecticut where it abuts New York State is marked by a panhandle in Fairfield County, containing the towns of Greenwich, New Canaan and parts of Norwalk and Wilton. This irregularity in the boundary is the result of territorial disputes in the late 17th century, culminating
One or more of the preceding sentences incorporates text from a publication now in the public domain: Chisholm, Hugh, ed. (1911). "Almandine". Encyclopædia Britannica. 1 (11th ed.). Cambridge University Press. p. 712.
One or more of the preceding sentences incorporates text from a publication now in the 
