Travertine

From the Tivoli quarries to the Colosseum, up to the modernism of Mies van der Rohe. Travertine is a stone that does not hide its genesis: its "voids" (vacuoles) tell the story of thermal springs, fossil vegetation, and millennial geochemical reactions.

Unlike marble (which undergoes immense underground pressure), travertine is a sedimentary rock that forms on the surface. Water rich in carbon dioxide and calcium, emerging from hot springs, releases CO₂ into the atmosphere, causing the rapid precipitation of calcium carbonate. During this layered sedimentation, the forming crust incorporates algae, mosses, leaves, and small insects. Over the centuries, this organic matter decomposes completely, leaving inside the stone the characteristic "holes" known as vacuoles. These macropores lighten the material and give it the unmistakable porous aesthetic.

Being a stratified rock, the appearance of travertine changes radically based on the direction in which the block is sawn in the quarry. The "Vein Cut" is performed parallel to the sedimentation lines, revealing continuous linear bands. The "Cross Cut" is done perpendicularly to the layers; the resulting surface loses the straight lines, showing a "cloudy" appearance and circular-shaped vacuoles. This directional choice determines not only the aesthetics but also the flexural strength of the slab.