from The American Heritage® Dictionary of the English Language, 4th Edition

  • n. A natural volcanic glass similar to obsidian but having distinctive concentric cracks and a relatively high water content. In a fluffy heat-expanded form perlite is used as a lightweight aggregate, in fire-resistant insulation, and in soil for potted plants.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • n. An amorphous volcanic glass formed by the hydration of obsidian
  • n. The lightweight insulating material and aggregate resulting from expanding the glass by heat.

from the GNU version of the Collaborative International Dictionary of English

  • n. Same as pearlite.

from The Century Dictionary and Cyclopedia

  • n. A peculiar form of certain vitreous rocks, such as obsidian and pitch-stone, the mass of which sometimes assumes the form of enamel-like globules.
  • n. See pearlite.


French (from perle, pearl, from Old French; see pearl1) or German Perlite (from Perle, pearl, ultimately from Vulgar Latin *pernula).
(American Heritage® Dictionary of the English Language, Fourth Edition)
From French perle ("pearl") + -ite (Wiktionary)


  • The name perlite (also spelled pearlite) comes from the French word perle which means pearl, in reference to the “pearly” luster of classic perlite.


  • The name perlite (also spelled pearlite) comes from the French word perle which means pearl, in reference to the "pearly" luster of classic perlite.

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  • A: Most potting soil or seed-starting media that you purchase in a garden center is pasteurized and contains inert material, such as vermiculite or perlite, which is sterile.

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  • The company has argued the contract changes to boost efficiency and productivity were necessary given the lower demand for perlite, which is used for liquid solid separations and in fillers for paints, coatings, polymers and elastomers.

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  • Lightweight Aggregate, such as perlite or vermiculite, can be added for special applications requiring overall weight reduction, additional thermal insulation or sound absorption.

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  • But "perlite" or not, there can be no question of the astounding stupidity of the West Indian rank and file, a stupidity amusing if you are in an amusable mood, unendurable if you neglect to pack your patience among your bag of supplies in the morning.

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  • Strip off the lower leaves and stick the stem into moist, soil-less mix, such as perlite and-or vermiculite.

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  • Even plants that usually grow on dry land—in soil—can be grown with their roots in a mineral-nutrient solution or in an inert medium, such as perlite, gravel, or something called mineral wool—fibers made from minerals or metal oxides.


  • A common ingredient in potting mixes is perlite, which makes the soils airier while also retaining moisture.

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  • The toenail clippers were put to the task, resulting in several choice stems that were given the rooting hormone routine and potted up into the mix of two thirds perlite to one third seed starting mix.

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