There are far more geological similarities than differences between travertine and limestone. Both are formed by the settling of plants, animals, sea shells, sand, and mud on the sea beds. As millions of years pass, this sediment continues to settle and the weight of additional settlement causes the limestone and travertine to compress and harden. This process creates the fossils frequently found in both of these stones. If, at this stage, hot water rich in carbon dioxide from hot springs percolates through the limestone and dissolves some of the stone leaving behind inclusions, holes or voids, travertine is formed. As the water resurfaces, the sudden drop in pressure and change in temperature causes the water to release carbon dioxide gas. The calcium carbonate or limestone then re-crystallizes as travertine.
During fabrication, the travertine tile inclusions can be filled and honed with an epoxy resin. At this point, It can be difficult to distinguish the finished travertine product from limestone. In most cases the epoxy resin is much harder and more durable than the stone. A frequent concern with filled and honed travertine products is that the fill comes out. Our experience has shown this not to be true. Rather, when inclusions are noted after fabrication, the suspected reason is that an inclusion always existed at that spot and that a thin layer of travertine stone had covered it, therefore preventing it from being filled with epoxy. During use of the product and with normal wear and tear, that thin layer wears down or breaks and pops through exposing the inclusion for the first time. An easy way to understand this is to think of travertine tile as a piece of Swiss cheese. As one slices through the cheese, new holes expose themselves. The repair for this is to fill the new inclusion with the same color grout used during the initial setting process since it is impossible to match the epoxy resin color and the grout technique is very easy for a homeowner to do himself.
Marble is created when the sedimentary stone (limestone or travertine) is exposed to heat and pressure over a long period of time. The stone undergoes a metamorphosis, it recrystallizes and becomes denser and harder. The recrystallization allows the marble to take a nice and beautiful polish finish during fabrication.
Another stone that takes a polish well is Granite. Technically, granite is a coarse-grained igneous rock even texture and color, composed chiefly of quartz and feldspars. The quartz and feldspars are what allows it to accept a “shine” or a polish. It can also contain small quantities of mica and other minor accessory minerals. Common belief is granite was solidified from molten rock (called magma) under pressure. Due to some granite showing minimal contact with surrounding walls, scientists debate whether granite was formed through an igneous or metamorphic process. Granite has been used since ancient times as a building material and it is known to be one of the oldest rocks on earth.
Regardless of the stones’ origin, travertine, limestone, marble, and granite all perform well if one understands the strengths and limitations of each stone. In some applications the inclusions from an unfilled travertine can work well to help create additional friction, however may not be suitable for very cold climates with extreme freeze/thaw conditions. A honed limestone can enhance the beauty of a contemporary living area when the slickness of polished marble is a concern. The key to selecting the proper stone for any application is to work with a very reputable dealer who understands the strengths and limitations of each stone and to ensure the stone is installed by a qualified and registered contractor.