Obsidian: Igneous Rock - Pictures, Uses, Properties - Geology.com
Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms are unable to arrange themselves into a crystalline structure. It is an amorphous material known as a " mineraloid." The result is a volcanic glass with a smooth uniform texture that breaks with a conchoidal fracture (see photo).
Obsidian - Wikipedia
Obsidian (/ ə b ˈ s ɪ d i. ən, ɒ b-/ əb-SID-ee-ən ob-) [5] is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. [6] Produced from felsic lava, obsidian is rich in the lighter elements such as silicon, oxygen, aluminum, sodium, and potassium.
Obsidian | Rock, Color, Composition, & Uses | Britannica
Obsidian is an igneous rock occurring as a natural glass that is formed by the rapid cooling of viscous lava from volcanoes. Where is obsidian found? Some of the best-known occurrences of obsidian are at Mount Hekla in Iceland, the Eolie Islands off the coast of Italy, and Obsidian Cliff in Yellowstone National Park, U.S.
Obsidian Rock : Properties, Formation, Occurrene and Uses Area
2023年11月8日 · Obsidian is an extrusive igneous rock. It is occurring as a natural glass formed by the rapid cooling of viscous lava from volcanoes. Result of this formed, glass occupies more than 80 % and that have seeming conchoidal fracture and vitreous luster. It usually colours dark, black, grey-black to grey.
Igneous Rocks | Pictures of Intrusive and Extrusive Rock Types
Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It cools so rapidly that crystals do not form. The specimen shown above is about two inches (five centimeters) across. Granite is a coarse-grained, light-colored, intrusive igneous rock that contains mainly quartz, feldspar, and mica minerals.
Obsidian Rocks: Identification, Characteristics, Pictures, and More
2024年4月26日 · Obsidian is a volcanic glass formed from the rapid cooling of lava. Its distinctive properties include a smooth, glassy texture, and it often appears jet black but can also have hints of red, brown, or green.
Obsidian: A Hard, Brittle Natural Volcanic Glass or Rock
2023年6月23日 · Obsidian is a hard, brittle, natural volcanic glass or mineraloid with a conchoidal fracture. It is not a mineral or crystal. However, it is often considered a volcanic or an extrusive igneous rock. Usually, obsidian is a rhyolite glass formed from rapid quenching viscous, silica-rich lava or magma.
Obsidian | AMNH - American Museum of Natural History
Obsidian is an "extrusive” rock, which means it is made from magma that erupted out of a volcano. If it was an igneous rock that formed from magma underground and did not erupt, it would have been called an "intrusive" rock.
Igneous Rocks Lesson #12 | Volcano World | Oregon State …
Some of the more common types of extrusive igneous rocks are lava rocks, cinders, pumice, obsidian, and volcanic ash and dust. This is the volcano Paricutin that is located in Mexico. It is erupting cinders and pumice which are examples of extrusive igneous rocks.
Obsidian geology: nature’s black glass - ZME Science
2024年1月11日 · Obsidian is a naturally occurring volcanic glass and one of the most striking types of igneous rocks. This article delves into what obsidian is, its formation and composition, the different...
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