Word: silica
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...through cracks in the crust, getting progressively hotter. It doesn't boil, despite temperatures reaching up to 400 degrees C, because it is under terrific pressure. Finally, the hot water gushes back up in murky clouds that cool rapidly, dumping dissolved minerals, including zinc, copper, iron, sulfur compounds and silica, onto the ocean floor. The material hardens into chimneys, known as "black smokers" (one, nicknamed Godzilla, towers 148 ft. above the bottom...
...earth's crust, known as plates, are colliding. Generally the weaker oceanic plates are forced beneath the thicker continental slabs. The friction of grinding rock, combined with heat welling up from the earth's interior, transmutes the lower edge of the oceanic plate into magma. Thick with silica, this type of magma tends to solidify near the surface, forming domes and plugs that seal off the channels through which the magma rises. Such blockages turn a volcano into a giant pressure cooker. At a certain point, when the surrounding rock is no longer strong enough to hold the expanding magma...
Concerned that their Neolithic treasures would quickly disintegrate if exposed to humidity and sunlight, museum officials placed them in a darkened room, under glass and resting on a bed of blue and white silica gel that absorbs moisture. To view the objects, visitors press a button, which turns on display lights (filtered to block any destructive ultraviolet light) for only 90 seconds...
...teeth can be bonded during a single visit to the dentist. Diluted phosphoric acid is applied to the natural tooth, etching microscopic pores into the enamel. Next comes a coat of liquid plastic to seal the tooth. Then a paste composed of plastic and finely ground quartz, glass or silica is patted on in thin layers tinted to match the natural teeth and molded into the desired shape. After each layer is applied, it is exposed for up to 40 seconds to either ultraviolet or visible light beams. This triggers a reaction that hardens and bonds the layer...
Post-flight inspections of the thermal protection system, a blanket of 31,000 silica tiles which protects the 122-foot long orbiter from the heat of reentry, revealed only minor damage and no missing tiles, White said. The tiles had been a problem on Columbia's first flight in April, and were a source of many of the delays that set the $10-billion shuttle project more than three years behind schedule...