vermiculite
/vəˈmɪkjʊlʌɪt
/noun [mass noun]
A yellow or brown mineral found as an alteration product of mica and other minerals, used for insulation or as a moisture-retentive medium for growing plants.Clay minerals are mainly illite and chlorite, with only traces of smectite, vermiculite and kaolinite....
- The deposit was interpreted to have formed by the replacement of biotite by vermiculite under the influence of pegmatitic fluids.
- These soil mixtures should include sand, peat moss, perlite, vermiculite, and fir bark for adequate drainage.
Origin
Early 19th century: from Latin vermiculari 'be full of worms' (because on expansion due to heat, it shoots out forms resembling small worms) + -ite1.