This article analyzes the classification of schist rock as felsic or mafic based on its physical and chemical characteristics.
Is Schist Felsic or Mafic? (EXPLAINED)
Schist is an interlayered felsic and mafic metamorphic rock that is foliated with minerals like tremolite, hornblende, chlorite, biotite, and muscovite.
Schistosity is the term used to describe the layering of these minerals.
The rock is densely packed with large mineral grains with interlocking silica crystals that are plainly visible in a hand specimen.
Carbonates are abundant in the rock, and the presence of feldspar and quartz at a glance suggests that it is a felsic rock, although there are some features that challenge this classification.
Characteristics of Schist
Physical Characteristics of Schist
Schist rock has a foliated texture with granular sizes ranging from small to medium.
Crystals can be seen in some instances due to their size.
The granules are extremely hard and vary in color from dark to light bands. It is often shiny due to the combination of these color tones.
Schist rock is formed after the compression of rocks that contain platy grains when pressure is exerted on the crust.
Some schists exhibit a green color as a result of extreme pressure and temperature.
Chemical Composition of Schist
The rock’s chemical composition is determined by its mineral constituents, which include hornblende, staurolite, kyanite, garnet-mica, muscovite-chlorite, and biotite.
However, the texture and mineral assemblages of the rock are dependent on the recrystallization pressure and temperature.
A foliated rock is one that easily splits into plates or sheets.
With increasing metamorphism and chemical composition, the grain size of the rock rises.
Where Schist can be Found
The formation of schist rocks is as a result of layering of rocks that were previously metamorphic, igneous, and sedimentary through a process of metamorphism.
Schist, which is considered the pre-cambrian rock, can be found in areas with eroded mountains or glacial deposition regions with eroded schist.
Uses of Schist
Schist has many industrial uses.
Due to its durability and strength, the rock is used in the building of walls and houses.
Houses built in Australia in the 1800s are still standing to this day.
It is also used for wall decorative purposes as well as jewelry.
What it Means When a Rock is Felsic or Mafic
A rock is classified as either felsic or mafic based on the silica content in it.
A rock that has at least 65 % silica is categorized as felsic, while one that contains less than 45 % silica is classified as mafic.
Additionally, there is the intermediate rock, which contains silica concentrations ranging from 45% to 65%.
Additionally, mafic rocks contain a higher proportion of magnesium and iron, whereas felsic rocks have a high concentration of feldspar and silica.
Additionally, mafic rocks are darker in color, whereas felsic rocks are lighter in color.
The categorization of a rock as felsic or mafic is significant because it signifies the probability of particular minerals being present in the rock, dependent on its classification.
A rock with a silica percentage greater than 65 % is classified as felsic and is more likely to include minerals such as potassium, aluminum, and silicon.
On the other hand, a darker-colored rock classed as a mafic rock is considered to contain a larger concentration of magnesium and iron, as well as trace amounts of silica.
All minerals contained in the two forms of rock are industrially useful, and understanding the type of rock found in certain locations can help in tracking mineral resources.
Is Schist Felsic or Mafic?
Schist is a metamorphic rock composed of felsic and mafic minerals such as tremolite, hornblende, chlorite, biotite, and muscovite.
Schistosity is the term used to describe how these minerals are layered.
The felsic and mafic layers and crystals are easily visible with the unaided eye, depending on the type of schist.
Having felsic and mafic characteristics suggests that it contains mineral components from both types of rock.
However, because the composition of the rock varies according to the type of schist formed, the silica content may not be precise.
The majority of schist types, on the other hand, are abundant in soft sheet and flaky silicate minerals.
Due to this property, schist is structurally weaker than granite and gneiss.
Schist is a layered felsic and mafic metamorphic rock crammed with large granules and interlocking silica crystals observable in hand specimens.
Due to the rock’s toughness and strength, it is often utilized in the construction of walls and houses.
Additionally, it is utilized as a decorative element on walls and in jewelry.
You might also like: