WebNov 28, 2024 · Spherulites is a specific texture that form during devitrification processes in obsidian. Spherulites are typically two-mineral aggregates (mainly quartz and feldspar), formed by initial... WebJul 25, 2008 · Spherulites are spherical clusters of radiating crystals that occur naturally in rhyolitic obsidian. The growth of spherulites requires diffusion and uptake of crystal forming components from the host rhyolite melt or glass, and rejection of non-crystal forming components from the crystallizing region.
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WebAbstract. The various forms of silica furnish us with the best and most complete example of polymorphism. In addition to the common minerals, quartz, ohalcedony, and opal, we … WebOct 19, 2012 · Spherulitic textures in the Rocche Rosse obsidian flow (Lipari, Aeolian Islands, Italy) have been characterized through petrographic, crystal size distribution … pounds per us dollar
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WebSpherulites in rhyolitic obsidian are composed primarily of alkali feldspar and SiO 2 polymorphs. Spherulites are often mm-scale, but are known to range from … WebOct 1, 2024 · Obsidian, or entirely glassy rhyolite, is ideal for tool making but not available locally. While not all rhyolite is glassy in texture, some varieties are glassy enough to be … Webspherulitic obsidian from Tequila volcano. Spherulites ranging in size from 1.0 to 8.0 mm in diameter are distributed homogeneously throughout. b Cathodilluminescence image showing fibrous alkali-feldspar crystals enclosed by oblate cristobalite masses within an individual spherulite. c Thin section image showing spherulites cross-cutting ... pounds project pg