Does Sandstone Contain Quartz?

Types of Sandstones

• There are three major types of sandstone: quartz sandstone, arkose sandstone and lithic sandstone. The length of time it took for the sediment to deposit is the determinant of what category a specific sample falls into. Quartz sandstone, which is also known as quartz arenite, takes a long time to form. Arkose sandstones are feldspars and are created through rapid erosion, the particular stresses of arid climates, and tectonic activity over steep slopes. These sandstones come in shades of brownish grey or pink. Lithic sandstones are also created through rapid erosion and the conditions of arid climates. These sandstones are about the size of a grain of sand and are dark in color.

Quartz

• Quartz is one of the most abundant minerals found on Earth; it's estimated that quartz makes up more than 12 percent of the mass of the planet's crust. It is a stable mineral that can survive over one billion years. Quartz can not only be found in sandstones, but also in igneous and metamorphic rocks. If the quartz is deep in the crust and experiences high temperatures and pressures, it can participate in rock and mineral formation.

Quartz in Sedimentary Rocks

• Quartz tends to accumulate in deposits of eroded material. This is due to its physical and chemical properties. It is a resistant material and is often formed from silicate materials during chemical weathering. Once formed, quartz will slowly weather on the surface. Here, it is only weathered by changes in temperature, erosion, cracking and grinding. Many sedimentary rocks that are formed on land have high levels of quartz.

Quartz in Sandstone

• Most sandstones are made up of quartz grains. Those that are comprised of more than 90-percent quartz are known as quartz sandstones. These sandstones can be quite porous and brittle or they can be hard. It depends on the shape of the quartz grains and the other minerals that help cement the sandstone together. Those sandstones that consist mainly of quartz grains are more durable and stable than those that contain other minerals such as calcite. The latter are more vulnerable to physical weathering, and they break apart readily in rainwater.