- a clay mineral, hydrous magnesium aluminum silicate, belonging to the montmorillonite group: found as a soft filling in rock cavities.
Origin of saponite
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- a clay mineral consisting of hydrated magnesium aluminium silicate and occurring in metamorphic rocks such as serpentine
C19: from Swedish saponit (a rendering of German Seifenstein soapstone), from Latin sāpō soap
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012