Why quartz is most common in detirtal sedimentary rocks?

Answer 1

The two most common elements in the Earth's crust are silicon and oxygen; when you combine them, you get silicon dioxide ... quartz. There's a lot of quartz in beach sand, because a) there's a lot of quartz period and b) quartz is not soluble in water.

In addition to being very plentiful, quartz is extremely resistant to weathering. As rock containing quartz and other minerals weathers and erodes, the rock particles are subjected to mechanical and chemical weathering. Along the route of erosional transportation via streams and rivers, quartz particles are among the most resistant to weathering and abrasion of rock minerals, and therefore the most plentiful. They are the survivors, so to speak.

Answer 2

Olivine is one of the most common minerals on Earth. It's known as one of the silicate minerals and it has the chemical formula (MgFe)2SiO4. With Mg and Fe in state of solid solution bonding single tetrahedra of SiO4 together.

The chemical stability of silicates is due to the relative inertness of the [SiO4] tetrahedra. Generally, when silicates are attacked by acids, the larger cations (i.e. Mg and Fe) are quite soluble. The chemical resistance of the mineral structure depends on the extent to which the tetrahedra are linked to each other. The stability of common silicates towards chemical weathering in the sedimentary environments increase in sequence, with Olivine (Nesosilicate or single tetrahedra) being the weakest and Quartz (Tectosilicate or framework silicate) being the strongest.

Olivine is easily one of the weakest silicates and, due to weathering, the cations (Mg and Fe) are removed easily from Olivine and it collapses because there is no linking between the SiO4 tetrahedra. Only a small fraction of the Si goes into solution. The majority of the SiO4 associates together to form colloidal SiO2, which are very small particles of precipitated Quartz.

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ADDED. The question was about Quartz! :-)

Quartz is pure or almost-pure silica (Silicon Dioxide) and its ubiquity in sand is solely due to it being one of the primary mineral in its igneous-rock sources, whilst also the most resistant to the weathering that releases the individual crystals. It is also released by the weathering of sandstone, but sandstone is a secondary, sedimentary rock whose material is sand derived from igneous rock - there's nothing new in "recycling"!

Answer 3

One of the reasons why quartz is one of the most common minerals found in sedimentary rocks is because of the abundance of its silicon component. Another reason is because of its resistance to chemical weathering.

Answer 4

The two most common elements in the Earth's crust are silicon and oxygen; when you combine them, you get silicon dioxide ... quartz. There's a lot of quartz in beach sand, because a) there's a lot of quartz period and b) quartz is not soluble in water.

In addition to being very plentiful, quartz is extremely resistant to weathering. As rock containing quartz and other minerals weathers and erodes, the rock particles are subjected to mechanical and chemical weathering. Along the route of erosional transportation via streams and rivers, quartz particles are among the most resistant to weathering and abrasion of rock minerals, and therefore the most plentiful. They are the survivors, so to speak.

Answer 5

This relates to the bowen's reaction series (http://jersey.uoregon.edu/~mstrick/AskGeoMan/geoQuerry32.html) This shows how the minerals start crystallizing from a solidifying magma. The last minerals to crystallize are those of the minerals lower down in the series, i.e. quartz. Quartz is also the most stable mineral, (i.e. very resistant to weathering and erosion).

In a rock, the first minerals to get weathered and eroded away are the minerals higher up in the series, i.e. olivine, plagioclase feldspar, pyroxene, biotite etc.... So, the minerals left will be mainly muscovite (mica) and quartz.

Quartz is composed of silica tetrahedrons. In this tetrahedron, one silicon atom is bonded to 4 oxygen atoms, much in the same way as the bonding in the allotrope of carbon: Diamond. This type of bonding is very strong, which partly explains the stability of quartz.

Answer 6

Quartz is chemically and physically stable on the earths surface making it vary durable. Only about 20% is found in igneous or metamorphic rocks yet is the most abundant mineral on the continental crust. It can be weathered down into smaller pieces but will remain quartz.

Answer 7

It is because quartz is more resistant to weathering and the process of erosion than is feldspar, and is more likely to be deposited as a result of its durability.

Answer 8

It is the most resistant mineral to chemical weathering.