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Following the atomic bombing of Hiroshima, it was discovered in 2016 that between 0.6% and 2.5% of sand on local beaches was fused glass spheres formed during the bombing. Like trinitite, the glass contains material from the local environment, including materials from buildings destroyed in the attack. The material has been called hiroshimaite ...
One common way in which lechatelierite forms naturally is by very-high-temperature melting of quartz sand during a lightning strike. The result is an irregular, branching, often foamy hollow tube of silica glass called a fulgurite. [2] Not all fulgurites are lechatelierite; the original sand must be nearly pure silica.
Such current may propagate into silica-rich quartzose sand, mixed soil, clay, or other sediments, rapidly vaporizing and melting resistant materials within such a common dissipation regime. [3] This results in the formation of generally hollow and/or vesicular, branching assemblages of glassy tubes, crusts, and clumped masses. [ 4 ]
Quartzite can have a grainy, glassy, sandpaper-like surface. Quartzite is a hard, non-foliated metamorphic rock which was originally pure quartz sandstone. [1] [2] Sandstone is converted into quartzite through heating and pressure usually related to tectonic compression within orogenic belts.
The high viscosity inhibits diffusion of atoms through the lava, which inhibits the first step in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava. [7] Obsidian is hard, brittle, and amorphous; it therefore fractures with sharp edges.
Purple and green pseudotachylyte veins in outcrop (Sierra Nevada Mountains, California) Pseudotachylyte (sometimes written as pseudotachylite) is an extremely fine-grained to glassy, dark, cohesive rock occurring as veins [1] that form through frictional melting and subsequent quenching during earthquakes, [2] large-scale landslides, and impacts events. [3]
Mineral dust is mainly constituted of the oxides (SiO 2, Al 2 O 3, FeO, Fe 2 O 3, CaO, and others) and carbonates (CaCO 3, MgCO 3) that constitute the Earth's crust.The composition of mineral dust, usually named in atmospheric sciences as mineralogy composition, is relevant for different physical and chemical processes in the atmosphere, for example, oxides with iron have an effect in the ...
It is generally glassy or fine-grained in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral assemblage is predominantly quartz, sanidine, and plagioclase. It is the extrusive equivalent of granite.