sedimentary

Travertine / Tufa (Porous Limestone)

Calcium Carbonate (predominantly Calcite, CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: Tan, beige, creamy-white to light brown; Luster: Dull, earthy; Crystal structure: Trigonal (microcrystalline calcite); Specific gravity: ~2.5 - 2.7 (lower bulk density due to high porosity).

Hardness: 3 on Mohs scale
Color: Tan, beige, creamy-white to light brown
Luster: Dull, earthy

Identified October 17, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed by the precipitation of calcium carbonate from mineral-rich spring waters, especially hot springs or subterranean groundwater emerging in limestone/karst environments. Highly vesicular and porous due to gas escape and organic matter decay during precipitation.

Uses & applications

Commonly used in building facades, paving stones, architectural tiles, indoor flooring, landscaping rock, and as an ornamental stone.

Geological facts

Much of the Colosseum in Rome and other famous ancient Roman monuments were constructed primarily from travertine quarried nearby in Tivoli, Italy.

Field identification & locations

Identified in the field by its porous, pitted, spongy texture, light tan/buff coloration, softness easily scratched by steel or a copper coin, and effervescence (fizzing) when exposed to dilute hydrochloric acid. Abundant in karst and geothermal areas worldwide.