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stalactite and stalagmite
stalactite and stalagmite , mineral forms often found in caves; sometimes collectively called dripstone. A stalactite is an icicle-shaped mass of calcite attached to the roof of a limestone cavern. Groundwater trickling through cracks in the roofs of such caverns contains dissolved calcium bicarbona...
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calcium carbonate
calcium carbonate CaCO 3 , white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. Calcium carbonate is largely insoluble in water but is quite soluble in water containing dissolved carb...
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squinch
squinch in architecture, a piece of construction used for filling in the upper angles of a square room so as to form a proper base to receive an octagonal or spherical dome. It was the primitive solution of this problem, the perfected one being eventually provided by the pendentive. Squinches may b...
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travertine
travertine , form of massive calcium carbonate, CaCO 3 , resulting from deposition by springs or rivers. It is often beautifully colored and banded as a result of the presence of iron compounds or other (e.g., organic) impurities. This material is variously known as calc-sinter and calcareous tufa a...
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pyrite
pyrite or iron pyrites , pale brass-yellow mineral, the bisulfide of iron, FeS 2 . It occurs most commonly in crystals (belonging to the isometric system and usually in the form of cubes and pyritohedrons) but is also found in massive, granular, and stalactite form. In spite of its nickname, "...
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Alhambra
Alhambra [Arab.,=the red], extensive group of buildings on a hill overlooking Granada, Spain. They were built chiefly between 1230 and 1354 and they formed a great citadel of the Moorish kings of Spain. After the expulsion of the Moors in 1492, the structures suffered mutilation, but were extensive...
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calcite
calcite , very widely distributed mineral, commonly white or colorless, but appearing in a great variety of colors owing to impurities. Chemically it is calcium carbonate, CaCO 3 , but it frequently contains manganese, iron, or magnesium in place of the calcium. It crystallizes in the hexagonal syst...
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minaret
minaret , tower, used in Islamic architecture, from which the faithful are called to prayer by a muezzin. Most mosques have one or more small towers, which are usually placed at the corners. The earliest structures specifically built as minarets were the four low square towers at the four corners ...
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cave
cave a cavity in the earth's surface usually large enough for a person to enter. Caves may be formed by the chemical and mechanical action of a stream upon soluble or soft rock, of rainwater seeping through soluble rock to the groundwater level, or of waves dashed against a rocky shore. Volcanic ac...
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dome
dome a roof circular or (rarely) elliptical in plan and usually hemispherical in form, placed over a circular, square, oblong, or polygonal space. Domes have been built with a wide variety of outlines and of various materials.
Early Domes
The earliest domes were probably roofed primitive ...
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