Light-weight, foam-like volcanic fragment
A form of volcanic glass, usually of felsic composition, so filled with holes from the escape of gas during quenching that it resembles a sponge and has very low density. (Compare Obsidian.)
A glassy igneous rock that forms from felsic frothy lava and contains abundant (over 50%) pore space.
Pumice - A volcanic glass, very light in weight.
Pumice is a light colored, frothy volcanic rock having the composition of rhyolite. It is often buoyant enough to float on water.
A light-colored volcanic rock containing abundant trapped gas bubbles formed by the explosive eruption of magma. Because of its numerous gas bubbles, pumice commonly floats on water.
A vesicular volcanic glass of granitic composition. It has so many vesicles that it has a very low specific gravity - sometimes low enough to float on water.
This volcanic rock was called pumax by the Romans. The name is related to their word for form, "spuma." Pumice is used for polishing hard things.
An exceptionally cellular, glassy lava, resembling a solid froth.
A light-colored, frothy volcanic rock typically composed of dacite or rhyolite glass. It is formed by the expansion of gas in erupting lava. Because of the numerous gas bubbles trapped in the rock, pumice commonly floats on water.
A light-colored cellular glassy rock commonly having the composition of rhyolite.
A rock consisting of frothy natural glass.
a light glass formed on the surface of some lavas; used as an abrasive
Cinder so bubbly that it floats in water.
A white, hard volcanic product used as an agricultural amendment
A light porous rock formed during volcanic explosions. Technically, pumice has no crystal structure and so is considered by geologist a glass. Pumice is ground into a powder for a variety of industrial uses including the manufacture of cement, cosmetic exfoliants, and metal polishes.
An igneous rock that is grayish or beige in color. It is formed when magma spills out out of earth so quickly that it became foamy, then rapidly cools and hardens.
volcanic rock formed during the explosive eruption of magma; it has numerous gas bubbles and floats on water.
A porous rock formed during explosive eruptions, generally of silica-rich magma. Gas dissolved in magma at high pressure comes out of solution as the magma ascends towards the earth's surface. This forms a froth which then fragments violently, driving the explosive eruption. Pumice clasts are pieces of the magmatic froth chilled to glass in contact with the air. Pumice commonly contains phenocrysts of plagioclase, hornblende, and magnetite. About 80% of many pumices are void space, causing them to float on water.
Light rock froth produced by the violent separation of gas from lava. Because of the many gas bubbles, some of this froth is so light that it floats on water.
Porous volcanic glass that is formed by the rapid expansion of gas bubbles in melt that is quenched as it is erupted.
Light-colored, frothy volcanic rock, usually of dacite or rhyolite composition, formed by the expansion of gas in erupting lava. Commonly seen as lumps or fragments of pea-size and larger, but can also occur abundantly as ash-sized particles. Usage of pumice.
It's a light-colored volcanic rock containing abundant trapped gas bubbles formed by the explosive eruption of magma. It's often used as a bonsai soil amendment.
Light weight porous rock of volcanic origin that acts as an exfoliator when rubbed on skin.
A light-colored volcanic rock containing lots of bubbles from trapped gases. This rock can sometimes float on water.
A light-colored, frothy, glassy volcanic rock. The texture is formed by rapidly expanding gas in erupting lava.
A fine pumice powder used in the polishing process. Usually available in 90 and 180 grades.
An abrasive agent used in many polishing procedures.
A volcanic rock that is so full of gas bubbles that it has a very low density. Pumice fragments can often float on water.
A rock froth, formed by the extreme puffing up of liquid lava by expanding gases liberated from solution in the lava prior to and during the solidification.
Light-colored, vesicular (filled with small cavities formed by entrapment of gases) glassy rock, similar in composition to rhyolite.
A natural soft, abrasive stone substance (similar to lava rock) used to clean pool tiles.
a white or gray, rock froth produced by the violent separation of gas from lava. Some of this froth is so light - because of the numerous gas bubbles - that it floats on water.
Pumice is bubbly frozen magma. Fragments of pumice are common on Montserrat and are essentially frothy light rock with a density similar to water (about 1 g/cc).
A fine abrasive powder that is made from volcanic ash. Pumice is used with a a felt block in woodworking to rub out (polish) a finish. (Pumice is also the gritty additive in Lava soap.)
A porous, lightweight, abrasive volcanic stone used to soften and polish hard tough, or callused skin.
A frothy rhyolitic volcanic rock full of gas holes. Usually floats on water. Abundant around Lake Taupo.
A light vesicular form of volcanic glass with a high silica content; it is usually light in color and will float on water.
Lava which has been ‘frothed up' by gases given off as a volcanic eruption takes place.
a light, poruous, glassy lava. Pumice is used, especially when powdered, for cleaning, smoothing, and polishing. [AHDOS
Pumice is a light-weight, spongy rock that is formed in explosive volcanic eruptions. This igneous rock is light and porous, containing a network of gas bubbles in volcanic glass and minerals. Pumice can form from any types of magma, including basalt, andesite, dacite, and rhyolite.
Pumice is a highly vesicular pyroclastic igneous rock of intermediate to siliceous magmas including rhyolite, trachyte and phonolite. Pumice is usually light in colour ranging from white, yellowish, gray, gray brown, and a dull red. Pumice has an average porosity of 90%.