rectorite
/ˈrɛktərʌɪt/Mineralogy
noun
A clay mineral of the montmorillonite group which occurs as large, soft, white or light brown leaves or plates.
- Rectorite is a basic aluminosilicate of sodium and calcium. Crystal system: monoclinic..
Origin
Late 19th century. From the name of E. W. Rector + -ite.