Rock and Mineral Review

Why is granite not considered a mineral?

• Granite is a rock because it is naturally occurring
• Granite is a rock because it is a renewable energy source.
• Granite is a rock because it does not have a definite chemical composition.
• Granite is a rock because it is hard and will never change its shape. 

Although brick, steel, and glass all come from substances found in Earth’s crust, they are not classified as minerals.  Why are they NOT classified as minerals?

• They are not classified as minerals because they are not naturally occurring.
• They are not classified as minerals because they have many uses.
• They are not classified as minerals because they are organic.
• They are not classified as minerals because they are too hard.

A science student wants to start her own rock collection.  She finds the following rocks in her backyard and records a description of each type of rock in the table above. Using this student’s detailed descriptions, classify each type of rock, and explain which evidence best supports the given answer.

• Rock 1 is a metamorphic rock because it has many visible pieces of rock pressed together.  Rock 2 is a sedimentary rock because it does not have any crystals.  Rock 3 is an igneous rock because it has bands which are similar to layers.
• Rock 1 is a metamorphic rock because it has many visible pieces of rock pressed together.  Rock 2 is an igneous rock because it does not have any crystals.  Rock 3 is a sedimentary rock because it has bands which are similar to layers.
• Rock 1 is a sedimentary rock because small rock fragments underwent the processes of compaction and cementation.  Rock 2 is a metamorphic rock because it has a glassy texture and formed from cooled lava.  Rock 3 is an igneous rock because it is foliated and formed by extreme pressure.
• Rock 1 is a sedimentary rock because small rock fragments underwent the processes of compaction and cementation.  Rock 2 is an igneous rock because it has a glassy texture and formed from cooled lava.  Rock 3 is a metamorphic rock because it is foliated and formed by extreme pressure

Students in Earth science were conducting an investigation to collect data on the characteristics of minerals. The diagram below shows three minerals undergoing physical tests, A, B, and C. Which sequence correctly matches each test, A, B, and C, with the mineral property tested and includes the results most useful for determining?

• A-streak; B-cleavage; C-hardness → most useful for determining the type of mineral
• A-streak; B-hardness; C-cleavage → most useful for determining the rate of weathering
• A-cleavage; B- hardness; C–streak → most useful for determining the rate of weathering
• A-cleavage; B-streak; C-hardness → most useful for determining the type of mineral

A mineral sample scratches fingernails, pennies, and glass but does not scratch steel as shown below.  What is the hardness of the mineral?

• About 4
• About 5
• About 6
• About 7

During a summer vacation in Hawaii, John found some rock samples to share with his Earth Science class.  All of the crystals were large and the rocks had a coarse texture. Based on this information which of the following statements is true about the rocks John found?

• The rocks were metamorphic
• The rocks were intrusive
• The rocks were extrusive
• The rocks were obsidian

What type of rock does magma form as it cools?

• igneous

• sedimentary

• metamorphic

Tara found a rock. She notices that she can rub off tiny grains of sand. The whole rock is made of sand. She thinks it is sandstone. How is this rock formed?

• sand grains were under pressure of the atmosphere and pressed together

• sand grains were brought together by molten lava reaching the surface

• sand grains were carried by wind and then cemented together

• sand grains were buried deep in Earth's crust and were heated.

In which location would you most likely find an igneous rock?

• in a deep cavern

• near a volcano

• on a sandy beach

• near the mouth of a river

Which of the following best explains the forces that cause a rock to change into a metamorphic rock?

• heat in the layers below the rock

• pressure in the layers above the rock

• pressure from above the rock layers above and heat from the magma