Rock Detective
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Approach:  One to one
Level: Year 8
Focus: Identifying rocks  
Resources:
Rocks (A,B,C,D), graph, descriptions card, recording book
296Kb
Questions/instructions:  
 
% responses
2007 ('03)
y8
In this activity you will be describing some rocks
and thinking about how they could have been
formed. Here are four rocks. Pick them up to see
what they are like. [Click on graphics to enlarge.]

Hand out rocks.		  
1. Here are some words to describe these rocks.
I want you to match the rocks with these descriptions.

Place descriptions card in front of student and read the descriptions to the student.
  
Description 1:
D - Pumice
99 (100)
Description 2:
A - Granite
52 (60)
Description 3:
B - Limestone
94 (93)
Description 4:
C - Schist
58 (68)
Now you are going to try and work out the names of the rocks using this graph. The graph shows how hard the different rocks are. The rocks are pumice, granite, limestone and schist.

Hand out graph.
  
2. Which rock do you think is pumice?
D
95 (95)
3. Which rock do you think is granite?
A
40 (52)
4. Which rock do you think is limestone?
B
57 (55)
5. Which rock do you think is schist?
C
34 (37)
6. Can you tell me about how one of these types of rocks was made?
prompt: Which rock? How was it formed?
Explanation:
Limestone (sedimentary rock):
- made from (crushed) sea
shells (of dead sea animals)
- buried together (with sand)
Schist (metamorphic rock):
- came from deep underground
- where it was pressured and
got very hot
- minerals grew (gives it
its silvery layers)
 Pumice (igneous rock):
- came out of a volcano
(volcanic lava)
- cooled/hardened quickly
- gas bubbles/air got trapped
in it (is full of holes)
Granite (igneous rock):
- hot rock (magma) underground
- cooled/hardened slowly
substantial, quite accurate
9 (10)
limited
27 (33)

Total score:
9–10
10 (14)
7–8
22 (28)
5–6
33 (33)
3–4
34 (24)
0–2
1 (1)
Subgroup Analysis [Click on charts to enlarge] :
Year 8
Commentary:
This popular task showed a moderate decline in year 8 student performance between 2003 and 2007.