In geology terms, different elements in contact with each other, under distinct conditions, will result in a special stone composition and texture. The properties of travertine stone, for example, are the obvious result of pressure in the moisturized environment. Travertine stone is a decorative stone that belongs to the category of porous limestone. The stones are actually made from sediments of hot springs and the holes in the rocks are caused by gases from these hot waters. 
The wide variety of colors and patterns of travertine stone make it an ideal and wide choice for designing building facades, pool walls and floors, and paving stones. In addition, there are many variations in the porosity and quality of the stone, which allows homeowners' hands open to choose. Travertine has thermal and acoustic resistant properties due to its holes. The travertine stone has acceptable resistance. This stone can be cut into wavy and non-wavy shapes. Among the travertine variants, white travertine stones with more uniform color stripes have higher quality. The presence of light-colored travertine can be attributed to the presence of dispersed iron oxide pigments in the texture of the travertine stone. The beautiful appearance of travertine is due to the varying levels of iron oxide in its various layers. 
Travertine geology
Travertine stone in the geology term is a limestone. generally, Limestone deposits are found on all the continents of the earth. Despite common and traditional references to "travertine marble", travertine is actually a type of limestone, as mentioned. It is actually a terrestrial (land) shaped version of limestone, in contrast to the marine formation of many other limestone variants. Limestone and travertine, like marble, are based on calcium carbonate and therefore change easily when exposed to weak acids. This group included a variety of stones, with absorption ranging from mild (<1%) to high (> 10%). The combination of acid sensitivity and absorbency limits the number of variants suitable for countertop applications, and users of limestone countertops should fully understand their properties to accurately predict their behavior during use. Its natural color is white, but travertine is also available in tan, cream, or rusty varieties. The red color of travertine and its varying intensity is due to the presence of iron carbonate. This natural stone is mostly formed in hot spring estuaries or in limestone caves, where various caves (cave structures) such as stalactites and stalagmites are formed. 
Travertine grain size
In the sedimentary stone classes, the size of the grain determines the name of the stone, whether it is limestone, dolostone, or travertine. Limestone, a sedimentary rock composed mainly of calcium carbonate (CaCO3), usually in the form of calcite or aragonite. It may also contain significant amounts of magnesium carbonate (dolomite); minor components that are also prevalent include clay, iron carbonate, feldspar, pyrite, and quartz. There are two sources of limestone:
- Biological precipitation from seawater, the main substances being lime-secreting organisms and foraminifera.
- Mechanical transport and deposition of native limestone to form clastic sediments. Travertine, tuff, limestone, chalk, pyroxene, and microcrystalline are all varieties of limestone.
Most of the limestones have a grainy surface texture. Their particle sizes range from 0.001 mm (0.00004 in) to visible particles. In many cases, these grains are microscopic fragments of fossilized animal shells. Limestone has long fascinated geoscientists because of its rich fossil content. Much of what is known about geochronology and evolution comes from studies of fossils embedded in limestone and other carbonate rocks. 
Travertine properties
As we discussed every type of stone has its own properties. So the travertine stone is not an exception. Travertine stones have beautiful patterns in texture compared to other types. These stones are layered and each layer has a different color than the other. Travertine has a porous texture and a variety of colors and stripes, the variation of colors manifests itself in different stripes due to differences in the compounds present in the stone elements during deposition. It is worth mentioning that because the chemical composition of these lines is different from the background of the stone, the resulting stone is less strong and forms a sensitive point on the stone with the least resistance to shock or pressure. The fewer the veins are, the fewer impurities, and the higher strength it would have. Travertine deposits are band-like, dense, and porous in texture, with pores of various sizes and shapes ranging from a few millimeters to several centimeters, sometimes reaching more than 10 centimeters in various travertine samples. Some travertine cavities are filled with secondary calcium carbonate deposits, such as aragonite and calcite minerals. Post-deposition events, such as dissolution and fractures, can increase porosity and permeability by two or more times. Travertine has pores and holes that need to be filled during surface treatment. The existence of holes causes cement mortar to seep into these holes during stone installation, preventing stones from falling. Travertines are muddy, for example, if the stone is wet and reaches an instant freezing temperature, the stone will be crushed. The beautiful travertine stone insulates sound, heat, and cold due to the many holes in its texture. Furthermore, thanks to these pores, they absorb cement and mortar very well, leading to an increased resistance to shrinkage and expansion of this product. Compared to other stones, this stone is lighter in weight, an advantage that reduces the load on the building. 
Travertine depositional environment
In the above context, it was mentioned that travertine is formed in an environment with the presence of a hot spring or circulating groundwater and depositional materials. This stone is formed when calcium carbonate is separated from water by evaporation. Travertine is often used as a decorative building block because of its ease of cutting. Travertine occurs in areas where calcium carbonate is commonly found in limestone and circulating groundwater. It is usually formed around the mouths of hot springs and in streams. The rock formations called stalactites and stalagmites found in the caves are mainly composed of travertine. When carbon dioxide-rich water seeps through rocks in a limestone area, the water dissolves the limestone (a typical karst process) and becomes saturated. When the environment through which the water flows changes significantly (such as a decrease in pressure and/or a change in temperature), the water releases carbon dioxide as a gas, like a carbonated beverage. The calcium carbonate then recrystallizes small dirt, shrubs, and living biological materials such as moss, algae and cyanobacteria are encapsulated. But biological material can survive and continue to grow on it. There are large deposits in Tivoli, Italy, near Rome. In fact, travertine has its name from the city. Tivoli was called Tibur in ancient Roman times. The ancient name of the stone is lapis tiburtinus, which means Tibur stone, which has fallen into travertine. Travertine forms 16 huge natural dams in the Croatian valley known as Plitvice Lakes National Park. Travertine adheres to moss and rocks in the water and has accumulated over thousands of years to form waterfalls up to 70 m. the example of this event can be seen in Band-i-Amir (Afghanistan), Pamukkale (Turkey), and other beautiful natural lake waterfalls that form behind travertine dams can be seen. 
Is travertine chemical or biochemical
Before answering the question, whether the travertine is sorted in the chemical class or in the biochemical one, it is important to know the differences between these two. Clastic sedimentary rocks are mainly composed of components that are transported as solid waste (clay, silt, sand, etc.). In contrast, chemical and biochemical sedimentary rocks are dominated by components (Na +, Ca2 +, HCO3-, etc.) that are transported as ions in solution. There is some overlap between the two, as almost all clastic sedimentary rocks contain cement formed by dissolved ions, and many chemical sedimentary rocks contain some clusters. The difference between chemical sedimentary rocks and biochemical sedimentary rocks is that in biochemical sedimentary rocks, organisms play the role of converting ions into sediments. This means that the existence and properties of biochemical sedimentary rocks are related to the life needs of the organisms that make them up. In chemical sedimentary rocks, this process is inorganic and is usually caused by water evaporation and the concentration of ions. Chemical and biochemical sedimentary rocks are classified according to the minerals they contain and are often dominated by a single mineral. It is true that some clastic sedimentary rocks, such as quartz sandstone, may also be dominated by a single mineral, but the reasons for this vary. Clastic sedimentary rocks can contain all the minerals present in the parent rock. The minerals that clastic rocks ultimately contain will depend on how much "processing" the sediment has been through physical and chemical weathering and transport before cementation. On the other hand, chemical sedimentary rocks are mainly limited to minerals that are very soluble in water. Limestone contains mineral materials like calcite and aragonite. The limestone can occur as a chemical sedimentary rock, formed inorganically due to precipitation, but most limestone is biochemical. In fact, limestone is one of the most common biochemical sedimentary rock examples. 
Travertine stone
Travertine is apparently an attractive stone categorized as a type of limestone. Its fibrous, marble-like texture and attractive earth tones make it one of the most popular building materials. Historically, most of the travertine used in architecture and art came from the mountains of Italy, but today most of the travertine sold comes from Turkey, Iran, Mexico, and Peru. As a flooring material, travertine is often sold as a tile and comes in a variety of earth tones, including tan, brown, rust, and beige. It is a very durable stone, and although it is easier to care for than some types of natural stone, travertine is very heavy and its porous nature requires you to regularly seal the surface. It does not work everywhere. However, properly installed and maintained travertine floors can add a unique mountain aesthetic to an interior space. Travertine stone is a common natural flooring material mostly used in bathrooms. Unpolished travertine has a natural slip-resistant texture. This makes it ideal for installation in bathrooms, showers, and floors. Travertine is a great stone to install around your pool if you live in a hot climate all year round. Travertine is neither as soft as marble nor as hard as granite. It can scratch if left unprotected, so be careful when moving heavy objects on travertine floors. Pay attention to the finish you choose and the area where it is installed. Like other natural stones, travertine can extend its timeless beauty with proper installation and maintenance. Proper installation plays an important role in the durability of travertine. The travertine price highly depends on the type you choose. Travertine may be one of the more reasonably priced stone options. Its reasonable price and rich appearance make travertine an affordable luxury.