sedimentary
Tufa (Calcareous Tufa)
Calcareous Tufa (Precipitated CaCO3)
AI-generated identification · may be incorrectHardness: 3 (Mohs scale), Color: tan, yellowish-brown to gray, Luster: dull to earthy, Structure: porous/vesicular, Cleavage: none, Specific Gravity: low (1.5-2.0 due to porosity)
Identified More sedimentary →
Explore Tufa (Calcareous Tufa) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (Mohs scale), Color: tan, yellowish-brown to gray, Luster: dull to earthy, Structure: porous/vesicular, Cleavage: none, Specific Gravity: low (1.5-2.0 due to porosity)
Formation & geological history
Formed by the precipitation of carbonate minerals from ambient temperature water bodies such as springs, lakes, and rivers. Often biologically mediated by algae or mosses during the Holocene or Pleistocene epochs.
Uses & applications
Used primarily in landscaping, aquascaping (African Cichlid tanks), and as a traditional lightweight building material in historical structures.
Geological facts
Tufa is often confused with Travertine; however, Tufa forms in ambient temperatures while Travertine forms in geothermal hot springs. It frequently contains imprints of organic material like leaves or twigs.
Field identification & locations
Identify by its highly porous, sponge-like appearance and its reaction (fizzing) to dilute hydrochloric acid. Commonly found near limestone springs and karst landscapes.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary