Natural stone has been used by humans since ancient times for a variety of needs. "Hard as stone," "Unyielding as a rock" are phrases commonly used in everyday speech, reflecting the recognition of the durability and longevity of natural stone.
The time has come when the use of natural stone in building finishes is becoming increasingly popular. This is related to the rise in citizens' prosperity, the desire to create a comfortable environment for leisure and living, to preserve (immortalize) and pass on such conditions as a legacy. Concepts such as ancestral estate are beginning to be revived.
🔍Fragment of the balustrade of the second level interior finishing of the atrium of the "Central Children's World" store in Moscow
Natural stone can have a wide variety of mineral compositions and colorations, but recently, preference has been given to carbonate rocks in beige colors. What is this connected with? The color beige (fr. beige), beige-light brown, with a creamy tint, a variant of human skin color or a grayish shade, a variant of wool color. This coloration is found in Jurassic limestone / marble depending on the choice of the layer of stone and the quarry from which it is extracted.
Brown (from "cinnamon," a diminutive of "bark," meaning "the color of bark") is a non-spectral color. The color index according to the international NCS scale is: S (5020-5040)-Y(20-30)R. It is formed by mixing black (gray), yellow, and red dyes or pigments.
Brown is widely found in nature; it is the color of tree bark, soil, fallen leaves, animal fur, well-brewed tea, chocolate, clay, and manure.
Civilization imposes a faster pace of life on a person. One must think faster, move faster, and also manage to shop and have fun. And there are so many temptations around, so much advertising and external stimuli. The information field simply invades a person's inner world without permission, imposing certain behavioral paradigms. Subconsciously, a person wants to escape this informational chaos and begins to strive for a cozy and calm environment. Comfort and tranquility evoke associations with a rural setting, and brown and beige - golden hues of color evoke associations with a cottage in the countryside and fields of wheat. That is why brown and beige tones of stone coloring are currently enjoying unusual popularity. Jurassic marble has a wide range of beige shades with inclusions of prehistoric inhabitants from the Jurassic period in dark brown color.
🔍Fragment of the interior finishing of the atrium of the "Central Children's World" store in Moscow
Among the variety of rocks, preference is given to carbonates.
This is not so much related to the fact that among intrusive igneous rocks (granites, syenites, diorites, gabbros), beige (brown) tones of color are very rare. Such rocks are very hard, shiny, which contradicts the association with wood and animal fur. On the other hand, limestones or marbles are quite soft, rough, and their surface contributes to a feeling of coziness, tranquility, balance, and serenity.
In addition, humanity willingly settled in caves during primitive times. Caves were typically formed in limestone. The memory of the presence of fossilized shells, mollusk shells, and corals in the limestone has remained in human subconscious since those times. The presence of fossilized shells in the cladding material associates with the reliability and protection of one's dwelling from all adversities.
Nevertheless, limestone varies from limestone. Among the variety of offered markets for cladding materials made of beige-toned limestones, one should only focus on those that are suitable for use in the conditions where you plan to exploit them. The color and pattern of the stone are undoubtedly an important factor here, but don't get burned by buying something that looks beautiful, which may turn into a rotten slab in the wall with streaks of poisonous colors in a year.
🔍Low-quality limestone turns into a rotten slab after a year.
How to determine the suitability of beige limestone
Ancient stone carvers year after year, for centuries, extracted stone from the same place, and this stone was used for construction right here, nearby. Builders and stone carvers, observing the stone, knew well which stone was suitable and which was not, and would deteriorate over time. The use of Jurassic marble dates back to the times of the Roman Empire, when it was used to construct fortifications and residential buildings. The rapid expansion of stone diversity in our time does not allow builders to accumulate experience in its use under various climatic conditions. In Russia, stone comes not only from the temperate climate of Central Europe – for example, Jurassic limestone – but also from the hot deserts of Egypt, Jordan, Tunisia, and the humid tropics of Brazil.
In such conditions, the suitability of the stone for stone cladding can initially be determined by visual inspection, based on the characteristic signs of unstable, prone-to-deterioration areas of the slab. More accurately and reliably, the strength of the stone and its stability (durability) are determined based on laboratory studies of its physical and mechanical properties.
Most of the beige limestones offered on the market today, from a petrological point of view, belong to the category of marbled limestones. Marbled limestones occupy an intermediate position between classic soft porous limestones (for example, chalk) and classic marble (Carrara marble, from which the famous Venus de Milo (Aphrodite) is made). The processes of marbleization occur under high pressures and temperatures as a result of the immersion of a section of the Earth's crust to depth during tectonic movements of large tectonic plates. Marbled limestones, in this case, acquire a number of valuable properties, which sometimes makes them even of better quality than classic marble.
Some marbled limestones become capable of achieving a mirror polish of excellent quality, and the compressive strength of such stones can increase multiple times and become comparable to the strength of granites. The porosity of marbled limestones is often very low, which makes them much more durable than marble.
It should be noted that any natural stone, even extracted from the same quarry, can vary significantly in quality, especially true for sedimentary rocks, which include limestones. The formation of the stone occurred over a long period of time, hundreds and thousands of years. During this time, the climate changed, which is reflected in the properties of the stone.
It is essential to keep this in mind when purchasing a stone of your preferred color from a showroom, especially from well-known brands. Both the famous statuary "Carrara" and the equally famous "Jurassic marble" may have "decay" and "wormholes" depending on which layer and from which location in the quarry this stone was extracted.
Currently, beige (brown) limestones with the commercial name "Jurassic Marble" (Germany) are gaining increasing popularity in the stone market of Russia. This stone has been used in Europe since ancient times and has proven itself very well in terms of both quality and color palette. However, few people know that in the quarries of "Jurassic Limestone," the stone is extracted from 25 layers, and not every one of them is suitable for cladding, especially under the conditions of operation in the megacities of Russia. Here, such a characteristic of the stone as frost resistance comes to the forefront. It is this property of the stone to withstand numerous cycles of alternating freezing and thawing that determines its durability.
Jurassic stone - limestone from Germany
Jurassic stone is a popular marbled limestone that has been used for decades around the world in both private villas and large projects – airports, shopping centers, administrative buildings. The stone is mined in Bavaria, in the southern part of Franconian Alb in the area of Eichstätt – in Weißenburg-Treuchtlingen. As for Jurassic limestone, it is a typical layered sedimentary rock that ideally consists of 27 layers with a layer height of 25-100 cm, of which, as a rule, the upper 26-27 layers are not used for the production of facade and floor tiles but are consumed as material for landscape architecture. There are more than 20 quarries for stone extraction, of which 9 belong to JuraLimestone GmbH; in each region, a special, unique type of product is extracted, not all types of layers and not all colors of stone are determined in a particular quarry, each has its own characteristics, and not all stone can be processed.
🔍Quarries for extracting Jurassic marble
In general, individual layers from 1 to 25 are recyclable. It is worth highlighting layer 11, which has a height of 130 cm and a striped structure with large open pores on a light beige background similar to travertine.
Other layers differ significantly in color, there are yellow ones (lower layers), milky ones (the stone quarry in Petersburgh – layer 15) and golden-yellow ones (upper layers, a dark yellow-brown tone), as well as gray-blue color. To obtain stone with the desired characteristics, the area where Jurassic stone is extracted should be studied and clearly delineated by layers that are typical for a particular part. Deviations from these delineations will lead to obvious differences from the expected variant.
This situation is very typical for Jurassic marble processed in the People's Republic of China. In most cases, the material for this market is purchased in blocks from quarries in Germany and shipped to China for cutting. However, it is necessary to distinguish between the stone purchased for specific projects in China and the one that will go for slab transshipment. In the first case, blocks of the required quality and from specific layers are purchased at a price that corresponds to the adequate German standard. In the second case, blocks are purchased on the principle of "buying what you see" at the minimum price, and consequently with all the resulting consequences.