Earth & SkyGreek → English
Smectite
/ˈsmɛktaɪt/noun
A group of clay minerals that swell dramatically when they take up water.
The Greek roots
σμήχειν
smḗchein
to wipe, to scour
Literally: “the scouring earth”
Follow a root:σμήχειν1 word
The story of the word
Greek fullers cleaned raw wool with a soapy clay they called σμηκτρὶς γῆ, scouring earth, from the verb for wiping something down. Mineralogists kept the name for the swelling clays, which now turn up in drilling mud, cat litter and face masks. The same verb gives medicine smegma, Greek for a cleansing unguent, and physics the smectic phase of liquid crystals, named for its soapy feel.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 19th century
Same family
smegmasmectic
In a sentence
Smectite in the subsoil is why the garden wall cracks every dry summer.
Drillers add smectite clay to keep the borehole from collapsing.