Pumice
**Pumice Properties and Formation**
– Composed of highly microvesicular glass pyroclastic with thin, translucent bubble walls.
– Commonly silicic, felsic, or intermediate in composition.
– Pale in color, ranging from white, cream, blue, or grey, to green-brown or black.
– Porosity of 64–85% by volume.
– Floats on water until waterlogged and sinks.
– Forms when frothy lava cools quickly after eruption.
– Lightweight due to trapped gas bubbles.
– Varies in color from white to gray.
**Global Distribution and Mining**
– Found globally from continental and submarine volcanic occurrences.
– Mined in various countries including Italy, Turkey, Greece, Iran, Chile, and Syria.
– Total world production in 2011 estimated at 17 million tonnes.
– Large reserves in Asia, Europe, North America, and South America.
– Europe is the largest producer with significant deposits in Italy, Turkey, Greece, Hungary, Iceland, and Germany.
– North America has mining operations in states like Nevada, Oregon, Idaho, Arizona, California, New Mexico, and Kansas.
– Chile is a leading producer in South America.
**Industrial and Commercial Applications**
– Used in construction as a lightweight aggregate.
– Employed in self-compacting concrete, oral hygiene products, pharmaceuticals, and hair care products.
– Effective in cleaning toilets, removing stains, and as an ingredient in various cosmetic products.
– Pumice powder is utilized in polishes, pencil erasers, stone-washed jeans production, water filtration, chemical spill containment, cement manufacturing, and horticulture.
**Historical and Cultural Significance**
– Pumice has a long history of use in various cultures.
– Employed in ancient Levant sites, Greek shores, and the book-making industry.
– Historical uses in pharmaceuticals, including treating ulcers and wounds.
– Used in early medicine for over 2000 years in treatments like teas for various ailments.
– Pumice has a place in the cultural history of hair care, toothpaste, and building construction.
**Environmental Impact and Marine Dispersal**
– Pumice mining is environmentally friendly due to its loose aggregate form on the earth’s surface.
– Raises environmental concerns in sensitive areas.
– Acts as a mechanism for long-distance dispersal of marine organisms.
– Floating pumice can travel thousands of kilometers and form rafts.
– Marine organisms can raft on pumice for extended periods.
– Pumice from volcanic eruptions like Krakatoa can drift for years.https://en.wikipedia.org/wiki/Pumice