Types of Rocks Worksheet - Free Printable

Explanation:
Let’s go step by step to label each rock and answer the questions.

Part 1: Label the rocks with correct rock types

There are 6 rock samples. We need to identify each as igneous, sedimentary, or metamorphic.

1. Top-left rock: Dark, porous (full of holes), looks like it cooled quickly from lava → This is igneous (specifically, *extrusive igneous*, like basalt or scoria).
2. Top-middle: Has a fossil (a fish) preserved in it → Fossils only form in sedimentary rocks (like limestone or shale).
3. Top-right: Layered, banded appearance, light-colored, smooth texture → This is metamorphic (e.g., *schist* or *gneiss* — formed under heat/pressure).
4. Bottom-left: Shiny, black, glassy, smooth fracture (conchoidal) → This is igneous (*obsidian*, formed from rapid cooling of lava).
5. Bottom-middle: Banded with red, brown, and black layers — looks like it was squeezed and heated → This is metamorphic (e.g., *banded gneiss* or *slate*).
6. Bottom-right: Contains visible crystals (like quartz and feldspar) in a coarse-grained, interlocking pattern → This is igneous (*intrusive igneous*, like granite).

Wait — let’s double-check #5 and #6:
- #5 (striped red/brown rock): Actually, if it shows clear layering *and* the layers are folded or wavy, it’s metamorphic. But if it’s just alternating colored layers without deformation, could be sedimentary. However, the texture looks shiny and foliated (like slate or phyllite), so likely metamorphic.
- #6 (gray with large crystals and speckles): Yes — classic intrusive igneous rock (granite). Sedimentary rocks usually have grains cemented together, not interlocking crystals.

But hold on — there are only 3 rock types, and we have 6 samples, so multiple samples can belong to the same type.

Let’s match standard examples:

- Porous dark rock → Igneous (e.g., pumice or scoria)
- Rock with fossil fish → Sedimentary
- Blocky layered light rock → Metamorphic (e.g., marble or gneiss)
- Black glassy rock → Igneous (obsidian)
- Striped colorful rock → Metamorphic (e.g., gneiss or schist)
- Speckled gray rock with crystals → Igneous (granite)

So labels:
1. Igneous
2. Sedimentary
3. Metamorphic
4. Igneous
5. Metamorphic
6. Igneous

✔ That fits: 3 igneous, 1 sedimentary, 2 metamorphic — common distribution.

Part 2: Answer the short-answer questions

1. *What is the difference between lava and magma?*
- Magma is molten rock underground.
- Lava is magma that has reached the Earth’s surface (i.e., when it erupts from a volcano).

2. *How are igneous rocks formed?*
- They form when magma or lava cools and hardens. If it cools underground → intrusive igneous (e.g., granite). If it cools on surface → extrusive igneous (e.g., basalt, obsidian).

3. *How are sedimentary rocks formed?*
- They form from layers of sediment (like sand, mud, shells) that get buried, pressed together, and cemented over time (called *compaction and cementation*). Fossils are often found in them.

4. *How are metamorphic rocks formed?*
- They form when existing rocks are changed by heat, pressure, or hot fluids — deep underground — without melting. The rock changes texture or structure (e.g., shale → slate, limestone → marble).

Now, since the worksheet asks to “Label the following rocks”, and there are blank lines under each image, the expected answers are the rock types in order:

Top row (left to right):
1. Igneous
2. Sedimentary
3. Metamorphic

Bottom row (left to right):
4. Igneous
5. Metamorphic
6. Igneous

And then the written answers as above.

Final Answer:
Igneous, Sedimentary, Metamorphic, Igneous, Metamorphic, Igneous
Lava is magma that has reached the surface; magma is underground molten rock.
Igneous rocks form when magma or lava cools and solidifies.
Sedimentary rocks form from accumulation, compaction, and cementation of sediments.
Metamorphic rocks form when existing rocks are changed by heat, pressure, or chemicals without melting.