Natural stone has been used by humans since ancient times for a variety of needs. Phrases like "hard as stone" and "unyielding as a rock," commonly used in everyday speech, testify to the recognition of the strength and durability 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 rising prosperity of citizens, the desire to create a comfortable environment for relaxation 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 of the 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 there has been a preference for carbonate rocks in beige colors. What is this related to? The color beige (fr. beige), beige-light brown, with a creamy tone, a shade of human skin color, or a grayish tint, a shade of wool. This coloration is found in Jura Limestone / marble depending on the choice of the layer of the 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 an accelerated 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 information chaos and begins to strive for a cozy and calm environment. Comfort and tranquility evoke associations with a rural setting, while brown and beige - golden tones of color evoke associations with a cottage in the countryside and fields of wheat. That is why brown and beige tones of stone color are currently enjoying unusual popularity. Jura Marble has a wide range of beige shades with inclusions of prehistoric inhabitants of 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 carbonate ones.
This is not so much related to the fact that among intrusive rocks (granites, syenites, diorites, gabbros) beige (brown) shades 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.
Moreover, humanity willingly settled in caves during primitive times. Caves were generally formed in limestones. The memory of the presence of fossilized shells, mollusk shells, and corals in limestones has remained in human subconscious since those times. The presence of fossilized shells in the cladding material is associated with the reliability and protection of one's dwelling from all adversities.
Nevertheless, limestone varies from limestone. Among the variety of beige-toned limestone cladding materials available on the market, one should only choose those that are suitable for use in the conditions where you intend to exploit them. The color and pattern of the stone are undoubtedly important factors here, but do not get burned by purchasing a beautiful-looking item that may turn into a rotten slab in the wall with streaks of toxic colors within a year.
🔍Low-quality limestone turns into a rotten slab after a year.
How to determine the suitability of beige limestone
Ancient stone masons year after year, for centuries, extracted stone from the same place, and this stone was used in construction right here, not far away. Builders and stone masons, observing the stone, knew well which stone was suitable and which was not, and over time would deteriorate. The use of Jura Marble dates back to the times of the Roman Empire, when it was used to construct fortifications and residential buildings. The rapid expansion of the variety of stone in our time does not allow builders to accumulate experience in its use in various climatic conditions. Stone comes to Russia not only from the temperate climate of Central Europe – for example, Jura 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 destruction areas of the slab. More accurately and reliably, the strength of the stone and its durability (longevity) are determined based on laboratory studies of its physical and mechanical properties.
Most of the beige limestones currently offered on the stone market, 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 subsidence 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 can achieve a mirror polish of excellent quality, and the compressive strength of such stones can increase many times, becoming 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 characteristic of 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 was reflected in the properties of the stone.
It is essential to keep this in mind when purchasing stone of a desired color from a showroom, especially from well-known brands. Both the famous statuary "Carrara" and the equally famous "Jura 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 "Jura Marble" (Germany) are gaining increasing popularity in the stone market of Russia. This stone has been used in Europe for a long time and has proven itself very well in terms of both quality and color palette. However, few people know that at the quarries of "Jura 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.
Jura Limestone - limestone from Germany
Jura Limestone 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 extracted in Bavaria, in the southern part of Franconian Alb, in the area of Eichstätt – in Weißenburg-Treuchtlingen. As for Jura 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 defined in a particular quarry, each has its own characteristics, and not all stone can be processed.
🔍Quarries for extracting Jura 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 (lower layers), milky (the stone extraction quarry in Petersbuch – layer 15), and golden-yellow (upper layers, a dark yellow-brown tone), as well as gray-blue color. To obtain stone with the desired characteristics, the area where Jura Limestone is extracted should be studied and clearly delineated by layers that are typical for a particular part. Deviations from these boundaries will lead to noticeable differences from the expected variant.
This situation is very typical for Jura 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 stone that will be used 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 German standard. In the second case, blocks are purchased on a "buy as you see" basis at the lowest price, and consequently with all the resulting consequences.