rocks and minerals worksheets Grade 3

📚 Topic Summary

Rocks and minerals are all around us! Minerals are naturally occurring, solid substances with a specific chemical composition and crystal structure. Rocks are made up of one or more minerals. Learning about rocks and minerals helps us understand the Earth's history and the resources we use every day. This worksheet will help you learn some key vocabulary and think critically about these amazing natural materials.

🧪 Part A: Vocabulary

Match the term with its definition:

1. Mineral
2. Rock
3. Igneous
4. Sedimentary
5. Metamorphic

Definitions:

1. A rock formed from cooled magma or lava.
2. A naturally occurring, inorganic solid with a definite chemical composition and crystalline structure.
3. A rock formed from the compaction and cementation of sediments.
4. A rock that has been changed by extreme heat and pressure.
5. A solid aggregate of one or more minerals.

🌍 Part B: Fill in the Blanks

Complete the sentences using the words provided: luster, hardness, color, streak, minerals.

The appearance of a mineral's surface in reflected light is called its __________. A mineral's __________ is its resistance to being scratched. __________ is not always a reliable property to identify a mineral because it can vary. The powder left behind when a mineral is rubbed on a streak plate is called its __________. Rocks are made of one or more __________.

Answers:

The appearance of a mineral's surface in reflected light is called its luster. A mineral's hardness is its resistance to being scratched. Color is not always a reliable property to identify a mineral because it can vary. The powder left behind when a mineral is rubbed on a streak plate is called its streak. Rocks are made of one or more minerals.

🤔 Part C: Critical Thinking

Imagine you are a geologist exploring a new planet. You discover a strange-looking rock. What are three tests you could perform to help identify the minerals that make up the rock? Explain why each test is useful.