أنواع الصخور الرسوبية والبركانية

Types of Rocks

There are several types of rocks, which can be categorized based on their mineral content, texture, and formation processes. Two of the most common types of rocks are sedimentary rocks and volcanic rocks.

Sedimentary Rocks

Sedimentary rocks are formed from sediments such as sand, silt, and clay that are laid down in layers and compacted over time. These rocks can be further classified into different types based on their mineral content and texture.

Clayey Rocks

Clayey rocks are a type of sedimentary rock that contains a significant amount of clay minerals. Clay is a very fine-grained material formed from the decomposition of feldspar and other minerals. Some examples of clayey rocks include:

• Kaolinite: This type of clayey rock is formed from the weathering of feldspar and is commonly used in the production of paper, ceramics, and refractories.
• Illite: This type of clayey rock is also formed from the weathering of feldspar and is commonly used in the production of paper, ceramics, and refractories.

Volcanic Rocks

Volcanic rocks are formed from magma or lava that cools and solidifies. These rocks can be further classified into different types based on their mineral content and texture.

Eruptive Rocks

Eruptive rocks, also known as magmatic rocks, are formed from the rapid cooling and solidification of magma. These rocks can be subdivided into two main types:

• Intrusive Rocks: Intrusive rocks, also known as plutonic rocks, are formed from magma that cools and solidifies slowly within the earth's crust. These rocks have a coarse-grained texture and are typically composed of minerals such as feldspar, quartz, and mafic minerals (olivine, pyroxene, and amphibole). Examples of intrusive rocks include granite and gabbro.

• Extrusive Rocks: Extrusive rocks, also known as volcanic rocks, are formed from magma that cools and solidifies quickly on the earth's surface. These rocks have a fine-grained texture and are typically composed of minerals such as feldspar, quartz, and mafic minerals. Examples of extrusive rocks include basalt and andesite.