How Minerals Form. Formation of Minerals. Geology, Mineralogy. Crystals, Igneous, Metamorphic

Which of the following is NOT one of the three types of rock?

• Metamorphic

• Magma

• Sedimentary

• Igneous

Answer explanation

The types of rock: igneous, metamorphic and sedimentary

The interlocking crystals of igneous rock help to classify it since these crystals are evidence of how the rock formed. The crystals are a result of–

• sediments being deposited.

•  particles forming layers.

• chemical reactions of minerals.

• melted rock that cooled.

Answer explanation

intrusive igneous rock forms when magma is trapped deep inside the Earth, where it cools very slowly over many thousands or millions of years until it solidifies. Slow cooling means the individual mineral grains have a very long time to grow, so they grow to a relatively large size.

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NGSS.MS-ESS2-1

NGSS.MS-ESS2-2

Which of the following processes produces metamorphic rocks?

• Rapid burial

• Gradual cooling

• Regular deposition

• Extreme pressure

Answer explanation

Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.

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NGSS.MS-ESS2-1

Which of the following processes is one of the first steps in the formation of some sedimentary rock?

• Rock is broken down into pieces.

• Liquid magma cools and hardens.

• Rock melts deep underground.

• Minerals change due to pressure.

Answer explanation

Clastic sedimentary rocks are made up of pieces (clasts) of pre-existing rocks.

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In order to be classified as metamorphic, a rock must–

• have been completely melted.

• change with heat and pressure.

• be made of small bits of larger rock.

• have formed very quickly.

Answer explanation

Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot mineral-rich fluids or, more commonly, some combination of these factors.

What is one of the most common processes that turns sediments into sedimentary rocks

• Organisms in the soil breaking down organic matter into useful chemicals

• Minerals within rock layers growing into large crystals over time

• Layers made of bits of broken rock pressing down on other layers

• Magma cooling under the surface of Earth, crystallizing to form rock

Lava that cools so quickly that crystals do not have time to form will lead to igneous rocks with a...

• Porphyritic texture.

• Coarse-grained texture.

• Glassy texture.

• Fine-grained texture.

Answer explanation

Quick cooling means that mineral crystals don't have much time to grow, so these rocks have a very fine-grained or even glassy texture.

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Each rock type can follow only one pathway of the rock cycle.

• True

• False

Which rock is formed form the cooling of volcanic ash on Earth's surface?

• Intrusive Igneous Rock

• Extrusive Igneous Rock

• Foliated Metamorphic Rock

• Organic Sedimentary Rock

Answer explanation

Extrusive, or volcanic, igneous rock is produced when magma exits and cools above (or very near) the Earth's surface.

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NGSS.MS-ESS2-1

The process in which dissolved minerals crystallize and glue sediment together.

• Compaction

• Deposition

• Organic Rock

• Cementation