Search results
Results From The WOW.Com Content Network
Magma rich in silica and poor in dissolved water is most easily cooled rapidly enough to form volcanic glass. As a result, rhyolite magmas, which are high in silica, can produce tephra composed entirely of volcanic glass and may also form glassy lava flows. [2] Ash-flow tuffs typically consist of countless microscopic shards of volcanic glass. [3]
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 ]
Helenite, also known as Mount St. Helens obsidian, emerald obsidianite, and ruby obsidianite, is a glass made from the fused volcanic rock dust from Mount St. Helens and marketed as a gemstone. [ 1 ] [ 2 ] Helenite was first created accidentally after the eruption of Mount St. Helens in 1980 .
Pele's hair, with a hand lens as scale Strands of Pele's hair under microscope view. Pele's hair (closest modern Hawaiian translation: "lauoho o Pele " [1]) is a volcanic glass formation produced from cooled lava stretched into thin strands, usually from lava fountains, lava cascades, or vigorous lava flows.
Rhyolite is an extrusive igneous rock, formed from magma rich in silica that is extruded from a volcanic vent to cool quickly on the surface rather than slowly in the subsurface. It is generally light in color due to its low content of mafic minerals, and it is typically very fine-grained or glassy. [5]
dragons-dogma-2-vernworth-entrance-cutscene. Most of Dragon’s Dogma 2 is spent traveling from place to place, and those places are often either dangerous dungeons, or quaint towns.
The expanded material is a brilliant white, due to the reflectivity of the trapped bubbles. Unexpanded ("raw") perlite has a bulk density around 1100 kg/m 3 (1.1 g/cm 3), while typical expanded perlite has a bulk density of about 30–150 kg/m 3 (0.03–0.150 g/cm 3). [2]
Scoria or cinder is a pyroclastic, highly vesicular, dark-colored volcanic rock formed by ejection from a volcano as a molten blob and cooled in the air to form discrete grains called clasts. [ 1 ] [ 2 ] It is typically dark in color (brown, black or purplish-red), and basaltic or andesitic in composition.