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carboloy
(Encyclopedia)carboloy kärˈbəloi [key] [portmanteau word from carbon and alloy], an alloy containing cobalt, tungsten, and carbon. This alloy is extremely hard, harder than steel; it is used to cut steel, porcel...silica
(Encyclopedia)silica or silicon dioxide, chemical compound, SiO2. It is insoluble in water, slightly soluble in alkalies, and soluble in dilute hydrofluoric acid. Pure silica is colorless to white. It occurs in sev...astrobleme
(Encyclopedia)astrobleme ăsˈtrōblēmˌ [key], large, circular structure ranging from c.1⁄2 mi to 40 mi (.8–64 km) in diameter. Astroblemes are found at numerous places on the earth's surface, e.g., Meteor, o...molybdenite
(Encyclopedia)molybdenite məlĭbˈdənīt, mō– [key], a mineral, molybdenum disulfide, MoS2, blue-gray in color, with a metallic luster and greasy feel. It occurs in crystals of the hexagonal system but more co...chronometer
(Encyclopedia)chronometer krənŏmˈətər [key], instrument for keeping highly accurate time, used especially in navigation. Before the advent of radio time signals it was the only device that provided the time ac...silt
(Encyclopedia)silt, predominantly quartz mineral particles that are between sand size and clay size, i.e., between 1⁄16 and 1⁄256 mm (1⁄406 –1⁄6502 in.) in diameter. Silt, like clay and sand, is a product...rhyolite
(Encyclopedia)rhyolite, fine-grained light-colored acidic volcanic rock. Rhyolite is chemically the equivalent of granite, and is thus composed primarily of quartz and orthoclase feldspar with subordinate amounts o...syenite
(Encyclopedia)syenite sīˈənīt [key], coarse-grained igneous rock, similar in appearance and composition to granite. Unlike granite, it contains little or no quartz. The chief minerals in syenite are the feldspa...sand
(Encyclopedia)sand, rock material occurring in the form of loose, rounded or angular grains, varying in size from .06 mm to 2 mm in diameter, the particles being smaller than those of gravel and larger than those o...sandblast
(Encyclopedia)sandblast, stream of sand or other abrasive particles driven by a jet of compressed air or water or by centrifugal force against a surface to clean or abrade it. When centrifugal force is used, the ab...Browse by Subject
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