One of the famous sedimentary and versatile rocks in the world is Limestone. It is a composition out of calcite which is one of the calcium carbonate minerals. limestone is known to be a biological sedimentary rock. Commonly it is formed out of the organic debris such as accumulation of shell, coral, algal, fecal, and etc. it needs shallow, soothed, warm and clear marine waters in order to be shaped. Because in this environment, organisms are capable of forming calcium carbonate out of skeletons and shells; and then they can easily extract the needed ingredients from ocean water. In some cases, when you look closely at a limestone's surface, even with a naked eye the fossils can be visible in its texture. Due to the location of the formation process of limestone, minerals involved and other environmental factors, some categories of limestones can have fine grain structures in different colors.

Various types of limestone

There are many ways that limestone's can be categorized. Due to the formation process and types of minerals involved, limestone has various groups. Here we will name some of them and briefly introduce them; then we will move on to discuss about a specific group called oolite limestone:

Calcarenite:

Calcarenite is a kind of limestone composed out of sand-sized grains of calcite which is usually in the form of tiny fossils, shell fragments or fossil debris. Some calcarenites stones contain oolites and when the amout of oolites are enough, the stone is called oolite limestone; which makes oolite limestone a sub-category of calcarenite.

Oolitic limestone:

Oolitic limestone is known to be a calcite cemented calcareous stone, consisting shell fragments which are non-crystalline in character. oolitic limestones can adjust to temperature changes without having any cleavage and keep an extremely uniform in composition and texture.

Dolomite:

Dolomite also known as magnesium limestone, is a sedimentary carbonate limestone which is mostly composed out of calcium and magnesium carbonate. Also dolomites are sedimentary rocks that should contain more than 50% of the mineral dolomites by weight.  

Coquina:

Coquina is another category of sedimentary rocks which is completely composed out of raw, unaltered shell fragments that are often quite large and loosely cemented by calcite. The coquina stones generally have a coarse and porous texture. You can frequently find oyster and sea shells fragments in their texture. The Coquina rock group can be considered to be a sub-category of calcarenite which is a detrital limestone of carbonate sandstones.

Microcrystalline limestone:

This type of limestones can be hard to recognize for ordinary people. Microcrystalline limestone is a metamorphosed limestone which is shaped by recrystallization of limestone due to a metamorphism process. It is composed out of very small crystals that cannot be seen without tools and magnification.

Travertine:

Travertine is another category of limestone that has an extremely porous and spongy texture which is usually deposited from solids in groundwater. It is one of the famous variety of limestone that has many different applications, especially in constructional projects. The pure travertine is in white color, but most of the time because of the presence of other minerals it can be seen in other colors like cream, tan, greenish, brownish and etc.

Tufa:

Tufa is another type of limestone that has a porous structure. It is the result of calcium carbonate precipitation from waters of a hot spring or other parts of surface water that can precipitate volumes of calcium carbonate. The pore space texture in tufa is the result of plant material trapped in precipitating process of calcium carbonate. Oolite limestone or as we mentioned earlier, egg stone is another category of sedimentary rock and limestones. It is belived that the oolite limestone are mostly considered to be shaped from the collection of calcium carbonate; this is not always true as oolite limestone can aslo be composed out of phosphate, dolomite or chert.

Appellation of oolite limestone

"òoion" is the ancient Greek word for egg which might be the main reason of the derivations associated with this geologic structure. Geologists have many ways for classifying sedimentary rocks. for instance, the sedimentary rocks can be classified based on the composition of the rock or by the diameter of the grains of oolite limestone structures that have shaped it and are observed within it. In conclusion, the "egg stone" title comes from this background.

Formation process of oolite limestone

Most of the oolitic limestones are formed in environments such as warm and shallow seas that contain a great amount of calcium with other minerals dissolved within the seawater. The intertidal movements can help through this process. they transport the material and aid in the formation of the ooid structures. this process can also take place in freshwater to, but it's not that common. The shell fragments and sand grains can provide for the calcium carbonate a medium in which the rock is shape. As the grains tumble around the sea bed they make layers of precipitated calcite, the amount and size of the ooid formed can indicate the length of time that the object has been exposed by sea water before getting buried by more sediment depositions.

Oolitic limestones properties and uses

Oolitic limestones are one of the popular natural stones among building materials for various applications. The oolitic limestones, have great properties such as durability and hardness, resist facing erosion and other environmental challenges, also they can be available in a many color and hues. Another useful feature of the oolitic limestones is that their blocks have an even structure; so they can be cut or shaped in any direction to make tiles with various forms and sizes. to prove the vast uses of oolitic limestone over the years; In the UK when you look around you will mostly find some old stone buildings in the town which are made out of oolitic limestone slab and tiles.

Suppliers

You should know that the classification between limestones -especially the of oolite limestones- and marble stones can be very hard and confusing at times to ordinary people. For instance, on the market you can find the same stone that has been marketed once as a limestone, in another place or time presented and sold as marble stone. So you should be cautious about the supplier that you choose.

Understanding and verifying chategories of limestones like oolite limestone, from marble stones is hard and a delicate process, because the only differences can be between grades and types of stones which are beyond the concern and expertise of any maintenance worker, building manager and even historical architect that has the responsibility of maintenance.

This confusion is understandable and relatable, but it does not mean that you can eliminate the need of finding the accurate identity of the materials. you will need the solid information when you want to plan the treating and maintenance schedule. In the end it is recommended to get your desired materials from known suppliers with good reputations.

Hunters Pavers have been a paver, blocks and retaining wall supplier in Australia for a long time, you can check our online reviews. Here at Hunter Pavers we can provide you all the information that you need. Even if you are not sure about a certain material we have a group of experts that can guide you through the process of finding the best and suitable material for your projects. Contact us, we will do our best to help you in any way we can.