Dictionary

rockwool en · NOUN

Etymology

From rock + wool.

Meanings

1. (countable, uncountable) Inorganic material resembling fiber, used primarily for insulation and soundproofing.
2. (countable, uncountable) A horticultural growing medium made from natural ingredients, usually including basalt rock and chalk.
   • In 1985, rockwool was introduced to the United States as an alternative to conventional soil and other soilless mediums. Rockwool is made of thin fibers of volcanic rock or a combination of volcanic rock, limestone, and coke. 1997, George F. Van Patten, Alyssa F. Bust, Gardening Indoors with Cuttings:

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