Travertine is one of several natural stones that are used for
paving patios and garden paths. It is sometimes known as
travertine limestone, sometimes as travertine marble; these are
the same stone, even though it is neither limestone nor marble.
The stone is characterized by pitted holes and troughs in its
surface. Although these troughs occur naturally, they suggest to
some eyes that considerable wear and tear has occurred over many
years. Some installers use a grout to fill these holes, whereas
others leave them open — travertine can even be purchased
"filled" or "unfilled." It can be effectively polished to a
smooth, shiny finish and comes in a variety of colors from grey
to coral-red. Travertine is most commonly available in tile
sizes for floor installations. Travertine is one of the most
frequently used stones in modern architecture, and is commonly
seen as facade material, wall cladding, and flooring. Architect
Welton Becket was one of the most frequent users of travertine,
incorporating it extensivel