Vocabulary: classify, extrusive igneous rock, foliation, fossil, igneous rock, intrusive igneous
rock, metamorphic rock, mineral, sedimentary rock, strata, texture
Prior Knowledge Questions (Do these BEFORE using the Gizmo.)
When you classify objects, you organize them into groups based on common characteristics.
[Note: The purpose of these questions is to activate prior knowledge and get students thinking.
Students are not expected to know the answers to the Prior Knowledge Questions.]
What are some different ways you could classify these marbles?
Answers will vary. Sample answer: The marbles can be
classified by size, color, or pattern.
1. What characteristics do you think scientists use to classify rocks?
Answers will vary. [Scientists classify rocks based on texture, composition, and how the
Rocks are classified by how they formed. The three types are:
Igneous rocks form from cooling magma or lava.
Sedimentary rocks form from the bonding of rock
fragments such as sand, silt, or clay; from organic
materials; and from chemicals dissolved in water.
Metamorphic rocks form when other rocks are
changed by heat and pressure.
In the Rock Classification Gizmo™, you will get to explore these three types of rocks. Think
about how each type of rock is formed.
1. Fossils are the remains of ancient plants and animals. Which type of rock do you think is
most likely to contain fossils?
2. Foliation occurs when minerals are flattened by heat and pressure. This results in a layered
or banded texture. Which type of rock do you think is foliated?
3. Air pockets can form in rapidly cooling magma or lava. In which type of rock would you
expect air pockets?