For many thousands of years, natural stone has been used by man in construction and design. The most popular are granite and marble. These two types of stone gained their popularity due to their strength and durability. Many people confuse these two stones. So let’s find out what is the difference between them and which of the stones is better.
Marble is a sedimentary rock that has a crystalline structure and consists of calcium carbonate and magnesium.
Marble has a pattern in the form of streaks or stains. The color of marble is light, but it can be different shades from yellow to black, due to impurities that are part of the stone.
Granite is a volcanic rock formed by the slow cooling and petrification of magma. It consists of 60-65% of feldspar (orthoclase and plagioclase), 20-30% of quartz and 5-10% of biotite, muscovite, and sometimes hornblende. Granite is mined in open pits.
Granite has an original grainy pattern. The colors of granite can be from pink to green and even black (gabbro).
Comparison of granite and marble
Compared to granite, marble is more soft, so its surface is better machined (polished). It should be noted that the stone has a high resistance to impact and is not prone to cracking and splitting. The high density of marble allows it to absorb virtually no moisture, which gives it high frost resistance and allows it to be used not only for interior decoration, but also outdoors.
The strength of granite is largely due to its density, which is more than twice the hardness of marble and gives it resistance to deformation and scratches.
Durability of products from both stones gives quite clear idea that granite or marble is stronger. Thus, the average service life of marble in the open air in our climate without the formation of cracks on its surface and other visible deformations can reach 110-160 years. This is quite a good figure compared to many other materials, but not granite.
The service life of granite is up to 600 years. That is, the durability of granite is 4-5 times longer than marble. This service life of granite is achieved due to its high resistance to temperature fluctuations and ultraviolet radiation.
When choosing between granite and marble for the manufacture of certain things, it is necessary not only to have a clear idea of what is stronger than granite or marble, but also to know about some properties of these stones during operation, affecting their appearance. For example, marble products are able to absorb certain acids and oils, which can lead to the formation of stains on the surface. White marble, which loses its original whiteness under the influence of climatic conditions, is especially prone to this. Granite is much more resistant to aggressive external environments, so it is able to maintain virtually unchanged appearance for several centuries.
Pros and cons
Marble is plastic, easy to polish and grind, unlike granite.
Marble is not as slippery as granite.
Granite is stronger than marble and more durable.
Granite is 4-5 times more durable than marble.
Marble is very sensitive to chemicals and high temperatures, compared to granite.
Where applicable
Granite is often used in the design of city bridges, in the lining of street stairs, buildings, for the manufacture of bar counters, kitchen and other countertops.
Marble is often used for cladding stairs and floors in baths and bathrooms, as well as for the construction of internal stairs. Marble is also actively used for interior decoration, cladding of buildings.
Radioactivity
There has been a lot of controversy recently about the radioactivity of marble and granite. So, the first thing to note is that the radiation background is really present in natural stone. But how dangerous is it?
Marble is safer in terms of radiation hazards, because all sedimentary and metamorphic rocks do not contain isotopes by their origin, and therefore safe.
Granite was formed as a result of a volcanic eruption, when magma comes to the surface, and for this reason it contains a certain number of isotopes. Radioactivity of granite is of 3 classes. Depending on the class of radioactivity, granite can be used in relevant areas of construction.
Marble and granite are checked for compliance with radiation standards at the stage of extraction when approving the reserves of the field. Then, in the laboratories of stone processing plants, the material is re-examined for radioactivity. There must be a radiation certificate for the natural stone. Ask the seller for it.
However, to be sure of the safety of the purchased stone, we advise you to check it with a radiometer. If you do not have it, but we recommend buying it, because the radiation background can be present not only in stone, but also in many building materials and interior items (eg, ceramic tiles, plumbing, building materials based on mineral binders).
According to nedra.com.ua
