出典:Wiktionary
出典:『Wiktionary』 (2026/05/21 22:20 UTC 版)
diatomaceous earth (uncountable)
出典:Wikipedia
出典:『Wikipedia』 (2011/07/02 16:43 UTC 版)
Diatomaceous earth (pronounced /ˌdaɪ.ətəˌmeɪʃəs ˈɜrθ/) also known as diatomite or kieselgur, is a naturally occurring, soft, siliceous sedimentary rock that is easily crumbled into a fine white to off-white powder. It has a particle size ranging from less than 1 micrometre to more than 1 millimeter, but typically 10 to 200 micrometres. This powder has an abrasive feel, similar to pumice powder, and is very light, due to its high porosity. The typical chemical composition of oven dried diatomaceous earth is 80 to 90% silica, with 2 to 4% alumina (attributed mostly to clay minerals) and 0.5 to 2% iron oxide.