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A glass is an amorphous solid completely lacking long range periodic atomic structure that exhibits a region of glass transformation.This broad definition means that any material be it organic, inorganic, metallic, etc. in nature may form a glass if it exhibits glass transformation behavior.
Ash-flow tuffs typically consist of countless microscopic shards of volcanic glass. [3] Basalt, which is low in silica, forms glass only with difficulty, so that basalt tephra almost always contains at least some crystalline material (quench crystals). [2] The glass transition temperature of basalt is about 700 °C (1,292 °F). [4]
Starting with the publication of research concerning lunar samples returned from the Moon, the consensus of Earth and planetary scientists shifted in favor of theories advocating a terrestrial impact versus lunar volcanic origin. For example, one problem with the lunar origin theory is that the arguments for it that are based upon the behavior ...
Libyan desert glass or Great Sand Sea glass is an impactite, made mostly of lechatelierite, [1] found in areas in the eastern Sahara, in the deserts of eastern Libya and western Egypt. Fragments of desert glass can be found over areas of tens of square kilometers. Like obsidian, it was knapped and used to make tools during the Pleistocene. [2]
Other materials, such as many polymers, lack a well defined crystalline state and easily form glasses, even upon very slow cooling or compression. The tendency for a material to form a glass while quenched is called glass forming ability. This ability depends on the composition of the material and can be predicted by the rigidity theory. [12]
Because it is often transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window panes, tableware, and optics. Some common objects made of glass are named after the material, e.g., a "glass" for drinking, "glasses" for vision correction, and a "magnifying glass".
Pages in category "Glass in nature" The following 26 pages are in this category, out of 26 total. This list may not reflect recent changes. A. Atacama desert glass;
The color of the glass is a pale bottle green, and the material is extremely vesicular with the size of the bubbles ranging to nearly the full thickness of the specimen." [ 3 ] The most common form of trinitite is green fragments of 1–3 cm thick, smooth on one side and rough on the other; this is the trinitite that cooled after landing still ...