Sandstone

What is written on the plate:

Sandstone

This medium-grained sandstone forms a "snapshot" of the Lower Permian landscape on its layer top. Dry cracks, grave marks and impressions of raindrops were preserved on the settled mud of a river floodplain after a flood. The sandstone slab shows a cast (negative relief) of the traces, which were covered by sand during the next flood.

Tambach-Formation, Rotliegendes/Unter-Perm, Steinbruch Bromacker,
Tambach-Dietharz, Thüringer Wald, ca. 285 Ma

Sandstone

Location: Tambach-Dietharz, Thuringian Forest

Age: ca. 285 million years

Sandstone is a clastic sedimentary rock containing at least 50% sand grains, which have a size between 0.063 and 2 mm according to the general grain size definition. The main component of sand grains is usually quartz, although they may be composed of various other minerals [1External link].

Sandstone is a sedimentary rock composed of mineral and rock fragments of different sizes. When the sand fraction makes up the majority (> 50%) of the mineral and rock fragments in a clastic sedimentary rock, it is commonly referred to as sandstone. There are different types of sandstone, depending on the composition of the sand fraction and other factors. For example, a quartz sandstone is composed of at least 90% quartz, while a sandstone with a high feldspar content is called arkose. Graywacke, on the other hand, contains a high percentage of clayey matrix and less than 75% quartz in the sand fraction [1External link].

Sandstones may also contain other minerals, such as primary calcium carbonate, resulting in calcareous sandstones. It is important to note that natural sand-lime bricks should not be confused with the man-made sand-lime bricks. Sandstones can also change to conglomerates or breccias depending on the proportion of larger grains, greater than 2 mm [1External link].

Sandstone has a wide range of characteristics. The color can vary from yellow to yellow-brown, red, green and black, depending on the minerals it contains, such as limonite, iron oxides, glauconite or bitumen. The grain size of sandstone is fine-grained and ranges from 0.06 to 2 mm. The microstructure varies from massive to well sorted flow structure. The density of sandstone ranges from 2.6 to 2.72 g/cm³ [2External link].

Sandstone is used in various fields due to its properties. In the construction industry, it was traditionally used for the construction of castles, churches and other representative buildings. Although modern artificial stones have largely replaced sandstone as a wall-building material in new buildings, it is still popular in other areas. Sandstone is used, for example, for flooring, stairs, facades.