Bible Dictionaries
Tufa

Webster's Dictionary

(1):

A soft or porous stone formed by depositions from water, usually calcareous; - called also calcareous tufa.

(2):

A friable volcanic rock or conglomerate, formed of consolidated cinders, or scoria.

Bibliography Information
Webster, Noah. Entry for 'Tufa'. Noah Webster's American Dictionary. https://www.studylight.org/​dictionaries/​eng/​web/​t/tufa.html. 1828.