sedimentary

Travertine (Tufa)

Chemical Sedimentary Limestone (CaCO3)

Hardness: 3-4 Mohs; Color: Tan, beige, white, cream with some iron staining; Luster: Dull to earthy; Structure: Highly porous, vesicular, or vuggy; Cleavage: Absent/irregular due to porosity; Specific Gravity: 2.5-2.7 (less if highly porous).

Hardness: 3-4 Mohs
Color: Tan, beige, white, cream with some iron staining
Luster: Dull to earthy

Identified April 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed by the precipitation of carbonate minerals from ambient/heated ground or surface waters, often near hot springs, limestone caves, or geothermally active areas. This specimen appears to be recent Holocene or Pleistocene in age.

Uses & applications

Travertine is used extensively as a building material, for tiles, garden sculptures, and architectural trim. Highly porous 'tufa' varieties are popular in rock gardens.

Geological facts

Famous structures like the Roman Colosseum were built primarily from Travertine. Its porous nature is often caused by the presence of CO2-producing organisms or water turbulence during precipitation.

Field identification & locations

Identify in the field by its porous, layered appearance and its strong reaction (effervescence) to dilute hydrochloric acid. Commonly found in karst landscapes and near geothermal features.

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