There are many more geological similarities than differences between travertine and limestone. Both are formed by the settlement of plants, animals, seashells, sand and mud on the seabed. 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 that are frequently found in both stones. If, at this stage, hot carbon dioxide-rich water from the hot spring seeps through the limestone and dissolves some of the stone leaving inclusions, holes, or voids, travertine is formed. As the water rises back to the surface, the sudden drop in pressure and change in temperature cause the water to release carbon dioxide gas. The calcium carbonate or limestone then re-crystallizes as travertine.
During manufacturing, travertine tile inclusions can be filled and polished with an epoxy resin. At this point, it can be difficult to tell the finished travertine from the limestone. In most cases, epoxy resin is much harder and more durable than stone. A frequent concern with filled and polished travertine products is that the filler bleeds out. Our experience has shown that this is not true. Rather, when looking at inclusions after fabrication, the suspect reason is that an inclusion always existed at that location and a thin layer of travertine had covered it, preventing it from being filled with epoxy. During the use of the product and with normal wear and tear, that thin layer wears away or breaks off upon first exposing the inclusion. An easy way to understand this is to think of travertine tile as a piece of Swiss cheese. As one cuts through the cheese, new holes are exposed. The remedy for this is to fill the new inclusion with the same color grout that was used during the initial setting process, as it is impossible to match the color of the epoxy resin and the grouting technique is very easy for the owner to do. .
Marble is created when sedimentary stone (limestone or travertine) is exposed to heat and pressure over a long period of time. The stone undergoes a metamorphosis, recrystallizes and becomes denser and harder. Recrystallization allows the marble to take on a nice, beautiful polished finish during manufacturing.
Another stone that polishes well is granite. Technically, granite is a coarse-grained igneous rock of uniform texture and color, composed mainly of quartz and feldspars. Quartz and feldspars are what allow it to accept a “shine” or polish. It may also contain small amounts of mica and other minor accessory minerals. The common belief is that granite solidified from molten rock (called magma) under pressure. Because some granites show minimal contact with the surrounding walls, scientists debate whether the granite formed through an igneous or metamorphic process. Granite has been used since ancient times as a building material and is known to be one of the oldest rocks on earth.
Regardless of the origin of the stones, travertine, limestone, marble, and granite work well if one understands the strengths and limitations of each stone. In some applications, the inclusions of an unfilled travertine can work well to help create additional friction; however, they may not be suitable for very cold climates with extreme freeze/thaw conditions. A polished limestone can enhance the beauty of a contemporary living room when the slipperiness of polished marble is a concern. The key to selecting the right stone for any application is working with a reputable dealer who understands the strengths and limitations of each stone and ensuring that the installation is performed by a qualified and registered contractor.
