The difference between travertine and other natural stones lies in the formation of the rock, the hardness of the stone and its appearance. Travertine is formed in hot springs and/or limestone caves. Travertine stone has holes within the stone which are caused by carbon dioxide evasion making it super porous and susceptible to staining if liquid is left on it. Travertine is comparable with marble in terms of hardness, ranking a 4 on the Mohs Hardness Scale. Travertine’s subtle veining adds texture to space without attracting too much attention. Widely appreciated for its versatility and longevity is evidenced in its extensive use in the Roman Colosseum.