Assyrian sculpture is the sculpture of the ancient Assyrian states, especially the Neo-Assyrian Empire of 911 to 612 BC, which was centered around the city of Assur in Mesopotamia (modern-day Iraq) which at its height, ruled over all of Mesopotamia, the Levant and Egypt, as well as portions of Anatolia, Arabia and modern-day Iran and Armenia. It forms a phase of the art of Mesopotamia, differing in particular because of its much greater use of stone and gypsum alabaster for large sculpture. Much the best-known works are the huge lamassu guarding entrance ways, and Assyrian palace reliefs on thin slabs of alabaster, which were originally painted, at least in part, and fixed on the wall all round the main rooms of palaces. Most of these are in museums in Europe or America, following a hectic period of excavations from 1842 to 1855, which took Assyrian art from being almost completely unknown to being the subject of several best-selling books, and imitated in political cartoons.The palace reliefs contain scenes in low relief which glorify the king, showing him at war, hunting, and fulfilling other kingly roles. Many works left in situ, or...

Aragonite is a carbonate mineral, one of the three most common naturally occurring crystal forms of calcium carbonate, CaCO3 (the other forms being the minerals calcite and vaterite). It is formed by biological and physical processes, including precipitation from marine and freshwater environments. The crystal lattice of aragonite differs from that of calcite, resulting in a different crystal shape, an orthorhombic crystal system with acicular crystal. Repeated twinning results in pseudo-hexagonal forms. Aragonite may be columnar or fibrous, occasionally in branching helictitic forms called flos-ferri ("flowers of iron") from their association with the ores at the Carinthian iron mines. Occurrence The type location for aragonite is Molina de Aragón in the Province of Guadalajara in Castilla-La Mancha, Spain, for which it was named in 1797. Aragonite is found in this locality as cyclic twins inside gypsum and marls of the Keuper facies of the Triassic. This type of aragonite deposit is very common in Spain, and there are also some in France.An aragonite...

White Sands National Park is an American national park located in the state of New Mexico and completely surrounded by the White Sands Missile Range. The park covers 145,762 acres (227.8 sq mi; 589.9 km2) in the Tularosa Basin, including the southern 41% of a 275 sq mi (710 km2) field of white sand dunes composed of gypsum crystals. This gypsum dunefield is the largest of its kind on Earth, with a depth of about 30 feet (9.1 m), dunes as tall as 60 feet (18 m), and about 4.5 billion short tons (4.1 billion metric tons) of gypsum sand. Approximately 12,000 years ago, the land within the Tularosa Basin featured large lakes, streams, grasslands, and Ice Age mammals. As the climate warmed, rain and snowmelt dissolved gypsum from the surrounding mountains and carried it into the basin. Further warming and drying caused the lakes to evaporate and form selenite crystals. Strong winds then broke up crystals and transported them eastward. A similar process continues to produce gypsum sand today.Thousands of species of animal inhabit the park, a large portion of which...

The Great Bath is one of the best-known structures among the ruins of the Harappan Civilization excavated at Mohenjo-daro in present-day Sindh province of Pakistan. Archaeological evidence indicates that the Great Bath was built in the third millennium BCE, soon after the raising of the "citadel" mound on which it is located. Features The Great Bath of Mohenjo-Daro is called the "earliest public water tank of the ancient world". It measures approximately 12 metres (40 ft) by 7 metres (23 ft), with a maximum depth of 2.4 metres (8 ft). Two wide staircases, one from the north and one from the south, served as the entry to the structure. A ledge 1.4 metres (4 ft 7 in) high extending the entire width of the bath is at the lower ends of these stairs. The sloping floor leads to a small outlet at the southwestern corner of the tank, connecting corbelled arch drain, which led the used water out of the bath.The floor of the tank was watertight due to finely fitted bricks laid on edge with a gypsum plaster, and the side walls were constructed in a similar manner. To make the tank even more watertight...

Acicular, in mineralogy, refers to a crystal habit composed of slender, needle-like crystals. Crystals with this habit tend to be fragile. Complete, undamaged acicular specimens are uncommon. The term "acicular" derives from the Late Latin "acicula" meaning "little needle". Strictly speaking, the word refers to a growth habit that is slender and tapering to a point. Prismatic crystals are not acicular; however, colloquial usage has altered the commonly understood meaning of the word. When writing for mineralogical publications, authors should restrict their usage of "acicular" to crystals with the tapering growth habit. To add to the confusion, some minerals are described with various morphological terms. For example, natrolite is often described as slender prismatic and millerite is often described as filiform or capillary. Examples Minerals with an acicular habit include mesolite, natrolite, malachite, gypsum, rutile, brochantite and bultfonteinite. Crystals of dimethyltryptamine have an acicular habit, but this substance is not regarded as a mineral by the International Mineralogical Association. An acicular...

Flowstones are sheetlike deposits of calcite or other carbonate minerals, formed where water flows down the walls or along the floors of a cave. They are typically found in "solution caves", in limestone, where they are the most common speleothem. However, they may form in any type of cave where water enters that has picked up dissolved minerals. Flowstones are formed via the degassing of vadose percolation waters.Flowstone may also form on manmade structures as a result of calcium hydroxide being leached from concrete, lime or mortar. These secondary deposits created outside the cave environment, which mimic the shapes and forms of speleothems, are classified as "calthemites" and are associated with concrete degradation. Formation Flowing films of water that move along floors or down positive-sloping walls build up layers of calcium carbonate (calcite), aragonite, gypsum, or other cave minerals. These minerals are dissolved in the water and are deposited when the water loses its dissolved carbon dioxide through the mechanism of agitation, meaning it can no longer hold the minerals in solution. The flowstone forms when...

Celestine (the IMA-accepted name) or celestite is a mineral consisting of strontium sulfate (SrSO4). The mineral is named for its occasional delicate blue color. Celestine and the carbonate mineral strontianite are the principal sources of the element strontium, commonly used in fireworks and in various metal alloys. Etymology Celestine derives its name from the Latin word caelestis meaning celestial which in turn is derived from the Latin word caelum meaning sky or heaven. Occurrence Celestine occurs as crystals, and also in compact massive, and fibrous forms. It is mostly found in sedimentary rocks, often associated with the minerals gypsum, anhydrite, and halite. On occasion in some localities, it may also be found with sulfur inclusions. The mineral is found worldwide, usually in small quantities. Pale blue crystal specimens are found in Madagascar. White and orange variants also occurred at Yate, Bristol, UK, where it was extracted for commercial purposes until April 1991.The skeletons of the protozoan...

Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the orthorhombic barium (baryte) and strontium (celestine) sulfates, as might be expected from the chemical formulas. Distinctly developed crystals are somewhat rare, the mineral usually presenting the form of cleavage masses. The Mohs hardness is 3.5, and the specific gravity is 2.9. The color is white, sometimes greyish, bluish, or purple. On the best developed of the three cleavages, the lustre is pearly; on other surfaces it is glassy. When exposed to water, anhydrite readily transforms to the more commonly occurring gypsum, (CaSO4·2H2O) by the absorption of water. This transformation is reversible, with gypsum or calcium sulfate hemihydrate forming anhydrite by heating to around 200 °C (400 °F) under normal atmospheric conditions. Anhydrite is commonly associated with calcite, halite, and sulfides such as galena, chalcopyrite...

Optimistic is the adjective form of the word optimism. Optimistic may also refer to: Optimistic bias in psychology Optimistic Cave, Korolivka, Borshchiv Raion, Ternopil Oblast, Ukraine; a gypsum cave "Optimistic" (Skeeter Davis song), 1961 "Optimistic" (Radiohead song), 2000 "Optimistic" (Sounds of Blackness song), 1991See also "Be Optimistic", a song performed by Shirley Temple from Little Miss Broadway An Optimistic Tragedy (play), a 1933 Soviet stageplay An Optimistic Tragedy (film), a 1968 Soviet film Optimistic concurrency control in computing Optimistic heuristic in computer science All pages with titles beginning with Optimistic All pages with titles containing Optimistic Optimist (disambiguation) Optimism (disambiguation) Optimization (disambiguation) Optimum (disambiguation)