cristobalite การใช้

• There is more than one form of the cristobalite framework.
• Silification is prominent and has formed cristobalite and tridymite.
• The Bariloche Atomic Centre reported that the ashes contain no crystal phases of quartz or cristobalite.
• In addition, the presence of structural water in opal makes it doubtful that opal consists of cristobalite.
• Thus although tridymite and cristobalite are common minerals in ignimbrites, they may not be primary magmatic minerals.
• Minerals associated with this include quartz, cristobalite and tridymite, which may all be present in volcanic ash.
• The high-temperature minerals, cristobalite and tridymite, have both lower densities and indices of refraction than quartz.
• Commonly in most felsic ignimbrites the quartz polymorphs cristobalite and tridymite are usually found within the welded tuffs and breccias.
• Other phases, e . g . the higher-temperature phases tridymite and cristobalite, are not significant for oscillators.
• Polymorphism can also result from the existence of different ?-quartz, tridymite, cristobalite, coesite, and stishovite.
• When devitrifying silica, cristobalite is usually the first phase to form, even when well outside of its thermodynamic stability range.
• Quartz has several polymorphs, including tridymite and cristobalite at high temperatures, high-pressure coesite, and ultra-high pressure stishovite.
• Silicosis is a fibrosing interstitial lung disease caused by inhaling fine particles of silica, most commonly in the form of quartz or cristobalite.
• Powder diffraction can distinguish between minerals that may appear the same in a hand sample, for example quartz and its polymorphs tridymite and cristobalite.
• In Pahrump Hills, an area about 39 feet lower, the minerals clay, hematite, jarosite, quartz, and cristobalite were found.
• Non-fibrous particulate materials that cause cancer include powdered metallic cobalt and nickel, and crystalline silica ( quartz, cristobalite, and tridymite ).
• Minerals formed by alteration processes include alunite, calcite, cristobalite, illite, jarosite, kaolinite, pyrophyllite, quartz, smectite, sulfur and tridymite.
• What appears to happen is that symmetry reduces the number of constraints so that structures such as quartz and cristobalite are slightly floppy and thus support some RUMs.
• Other contaminants-- cristobalite, barium, cadmium, copper, zinc and mercury-- exceeded the levels in fewer than 5 percent of the samples tested.
• For example, quartz will change into a variety of its SiO 2 polymorphs, such as tridymite and cristobalite at high temperatures, and coesite at high pressures.