Question

What is the most abundant mineral group in Earth's crust? What elements always are found in the minerals included in this group?

Short answer

Silicates; they always contain silicon and oxygen.

Step-by-step solution

Determine the Most Abundant Mineral Group

The most abundant mineral group in Earth's crust is the silicate group. Silicates are known for their widespread abundance and comprise the majority of minerals found in crustal rocks.

Identify Elements in Silicates

Silicate minerals always contain silicon (Si) and oxygen (O) as their fundamental components. This is because the basic building block of all silicates is the silicon-oxygen tetrahedron, \[ \text{(SiO}_4^{4-}\text{)} \]

Key concepts

Earth's crust

The Earth's crust is the outermost layer of our planet. It is like a thin shell that covers the Earth and is where we live. The crust is made up of a variety of rocks and minerals. These rocks and minerals make up the landscape we see every day.

Even though it's not very thick compared to the other layers of the Earth, the crust is extremely important because it contains all the materials we use in our daily lives, such as metals and other resources.

• The Earth's crust is divided into two main types: the continental crust and the oceanic crust.
• The continental crust is mostly comprised of less dense rocks such as granite.
• Oceanic crust is made up of denser rocks like basalt.

Understanding the composition of the Earth's crust helps us learn what minerals are present and why certain types are more abundant.

silicon

Silicon is a chemical element represented by the symbol Si on the periodic table. It is the second most abundant element in the Earth's crust, right after oxygen. Silicon is not only significant because of its abundance but also because of its role in forming minerals.

Being part of the silicate minerals, silicon pairs with oxygen to create the foundation of numerous rock-forming minerals.
Silicon serves as a key building block because:

• It bonds easily with oxygen, leading to the formation of the silicon-oxygen tetrahedron.
• It contributes to the formation of various complex structures, supporting the crust's stability.

The role of silicon extends beyond just forming minerals, as it is also critical in manufacturing electronic parts like computer chips.

oxygen

Oxygen is the most abundant element in the Earth's crust. It is highly reactive and forms compounds with almost all elements, significantly impacting geological processes. In the silicate minerals prevalent in the Earth's crust, oxygen plays a central role by combining with silicon.

Here are some key features of oxygen in geology:

• Critical for the formation of the silicon-oxygen tetrahedron, which is the building block of silicate minerals.
• Oxygen's abundance and reactivity contribute to the formation of a wide variety of minerals.

Apart from its geological importance, oxygen is crucial for life, being a major component of water and essential for the survival of most living organisms.

silicon-oxygen tetrahedron

The silicon-oxygen tetrahedron is a fundamental structural unit in Earth's crust, particularly in silicate minerals. It consists of a single silicon atom surrounded by four oxygen atoms positioned at the corners of a tetrahedron. This configuration results in the chemical formula \[ \text{SiO}_4^{4-} \].

This structure is important because it is the building block of all silicate minerals, which are the most abundant mineral group in the crust.

• The strong covalent bonds between silicon and oxygen give these minerals their stability and resistance to weathering.
• The tetrahedra can link together in various ways, forming chains, sheets, or three-dimensional frameworks, leading to a wide variety of minerals with different physical properties.

Understanding the silicon-oxygen tetrahedron helps in comprehending how different types of rocks and minerals form and persist in the Earth's crust.