Yesterday, our class began a rock lab, starting with a problem and then diving into hands-on activities. Here’s a look at what they did:
The Problem
We began the lab with a practical challenge: Harry’s teacher asked him to sort his rock collection into three categories—sedimentary, metamorphic, and igneous. Our goal was to help him figure out how to classify his rocks correctly.
Test 1: Identifying Rock Types
To address Harry’s problem, we first examined the appearance of various rocks. We focused on the following characteristics:
- Sedimentary Rocks: Identified by their layered structure and the potential presence of fossils.
- Igneous Rocks: Noted for their crystal formation, with crystal size revealing the cooling rate of the lava.
- Metamorphic Rocks: Recognized by their crystalline texture and sometimes visible bands.
Tools Used:
- Magnifying glasses
Process:
- Students used magnifying glasses to closely observe each rock.
- They recorded their distinctive features and tried to classify each rock according to its appearance.
Test 2: Testing Rock Hardness
Next, we tested the hardness of the rocks. This helped us further differentiate between the types:
- Hardness Test: We compared how easily each rock could be scratched or worn down. Generally, igneous and metamorphic rocks are harder than sedimentary rocks, with igneous rocks being the hardest.
Tools Used:
- Popsicle sticks
- Sandpaper
Process:
- Students rubbed the rocks in their hands to see if they crumbled or left residue.
- They attempted to scratch each rock with the popsicle sticks and sandpaper. Harder rocks were more resistant to scratching.
- They worked on arranging the rocks from softest to hardest.
We have 3 more tests to conduct in our rock lab, stay tuned!
