the lesson on rocks and types of rocks,guides me to ponder on
Answers
There are three kinds of rock: igneous, sedimentary, and metamorphic. Igneous rocks form when molten rock (magma or lava) cools and solidifies. Sedimentary rocks originate when particles settle out of water or air, or by precipitation of minerals from water. They accumulate in layers.
the lesson on rocks and types of rocks,
Introduction
There are three types of rocks: igneous, sedimentary and metamorphic. Each of these types is part of the rock cycle. Through changes in conditions one rock type can become another rock type. Or it can become a different rock of the same type.
What Are Rocks?
A rock is a naturally formed, non-living earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass.The different colors and textures seen in this rock are caused by the presence of different minerals.
How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger.
Three Main Categories of Rocks :
Rocks are classified into three major groups according to how they form. Rocks can be studied in hand samples that can be moved from their original location. Rocks can also be studied in outcrop, exposed rock formations that are attached to the ground, at the location where they are found.
Igneous Rocks
Igneous rocks form from cooling magma. Magma that erupts onto Earth’s surface is lava. The chemical composition of the magma and the rate at which it cools determine what rock forms as the minerals cool and crystallize.
Sedimentary Rocks
Sedimentary rocks form by the compaction and cementing together of sediments, broken pieces of rock-like gravel, sand, silt, or clay . Those sediments can be formed from the weathering and erosion of preexisting rocks. Sedimentary rocks also include chemical precipitates, the solid materials left behind after a liquid evaporates.
Metamorphic Rocks
Metamorphic rocks form when the minerals in an existing rock are changed by heat or pressure within the Earth.