Made by exposing perlite to heat, which causes the trace water contained in the perlite to expand, popping the perlite like popcorn.
Perlite is a substance that has many commercial and industrial uses. Also known as volcanic glass, perlite is used in agriculture, shipping, medicine and a host of other applications. 1  Alternatives to Perlite. 2  Is Perlite Toxic? Also known as volcanic glass, perlite is used in agriculture, shipping, medicine and a host of other applications. Other People Are Reading. Perlite is an amorphous volcanic glass that has a relatively high water content, typically formed by the hydration of obsidian. It occurs naturally and has the unusual property of greatly expanding when heated sufficiently. Perlite mine in Owens Valley, California. Perlite is a non-renewable resource. The world reserves of perlite are estimated at 700 million tonnes. In 2011, 1.7 million tonnes were produced, mostly by Greece (500,000 t), United States (375,000 t) and Turkey (220,000 t). However, no information for China – a leading producer – was available Making the world better, one answer at a time. Perlite is an amorphous volcanic glass. Perlite is created from a mixture of hydrated obsidian and mass amounts of water. 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). Perlite mine in Owens Valley, California. Perlite is a non-renewable resource. The world reserves of perlite are estimated at 700 million tonnes. In 2011, 1.7 million tonnes were produced, mostly by Greece (500,000 t), United States (375,000 t) and Turkey (220,000 t). However, no information for China – a leading producer – was available Description: Perlite is an amorphous volcanic glass (SiO 2) that has relatively high water content, typically formed by the hydration of obsidian. Perlite has the unusual characteristic of expanding and becoming porous when it is heated. Perlite is a volcanic rock mined in the United States, as well as other countries like China, Greece, and Italy. The volcanic glass, or perlite, is formed when lava (molten rock) spews out of a volcano, and cools in a rapid manner. Because of rapid cooling, water is trapped within the rock, and the lava forms into a glass-like structure. Also known as volcanic glass, perlite is used in agriculture, shipping, medicine and a host of other applications. Other People Are Reading. Vermiculite mined at a plant in Libby, Mont., once the main source of the material, was found to be contaminated with asbestos fibers. Though the plant was closed and the industry reformed, people have, to some degree, made the switch to perlite. Perlite is made from a mined volcanic glass of the same name. As a raw material it contains water, trapped by the rapid cooling of lava. The moisture vaporizes explosively when heat is applied.  Definition: Perlite is a form of volcanic glass that is mined all over the world. Horticultural perlite is made by exposing perlite to heat, which causes the trace water contained in the perlite to expand, popping the perlite like popcorn. The result is a very lightweight, white stone-like substance. Perlite is considered a nuisance dust by regulatory agencies, which means that efforts should be made to control perlite dust. Eye and mouth protection are recommended to prevent the dust from being ingested. Perlite dust can aggravate existing respiratory conditions and cause eye irritation.
http://www.ehow.com/about_5402928_perlite.html https://en.wikipedia.org/wiki/Perlite http://www.answers.com/Q/What_is_perlite_made_of https://en.wikipedia.org/wiki/Perlite http://www.mineralseducationcoalition.org/minerals/perlite http://www.ehow.com/about_5402928_perlite.html https://www.washingtonpost.com/lifestyle/home/get-to-know-your-potting-mix-vermiculite-and-perlite/2014/03/25/c0385bf2-add0-11e3-b8b3-44b1d1cd4c1f_story.html http://houseplants.about.com/od/glossar1/g/Perlite.htm
what is perlite made of?