Travertine is a sedimentary rock form by the accumulation and precipitation of calcite and carbonate minerals from springs, glaciers, oceans and rivers. Heat and pressure compress the sediment deposits into layer beds or strata. The succeeding layers build on the previous layers and the result is inconsistence in color and appearance. The chemical formation also makes them quite porous and permeable.
The introduction of minerals during its formation gives travertine its many colors. These minerals can give it anything from an ivory, cream, beige and walnut to gold color. Red travertine tiles are due to iron compounds. Cement or synthetic resins will cover any pores on travertine tiles. They may also be left unfilled to have a distinguished, unpolished appearance. Honed (matte) is the most common finish for travertine. Others are polished, brushed and tumbled, or textured surface finish.
Travertine is used as façade material such as claddings on buildings, kitchen floor tiles, bathroom tiles, countertops, and paving for patios and garden paths. Travertine reacts to acids such as vinegar and citrus juices so consideration must be given on their environment. Sealers must be applied to keep it protected.