Transcript Rocks and Minerals Lesson 4

BIG IDEA:
Rocks and minerals have properties
that can be: observed, tested,
described, identified and recorded.
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What does the object look like?
Where have you seen it before?
What is it used for?
What do you think it is?
Mr. Maxwell came by to see how you were coming with
identifying his rocks and mineral collection. He was
very impressed with the data you recently collected
for the luster test and hopes you will be able to
identify all of his collection since many appear to have
similar properties Today we are going to use more of
the information and materials provided by our geologist
to test the hardness of each mineral. A geologist will
often use a Mohs Scale of Hardness to help identify
and compare minerals.
What does the principal and geologist want us to do?
What did the geologist give us to help?
What is the problem in this investigation?
How can we …
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A volunteer will assist me with a simple
demonstration. The volunteer will scratch
the tip of a nail against a piece of chalk.
Do you think the nail will scratch the chalk,
or will the chalk scratch the nail?
Which object is harder; the chalk or the
nail?
I think that we can…because…
Hardness
The resistance of the surface of a mineral to
scratching by another substance.
Mohs Scale of Hardness
A scale that ranks the hardness of minerals
compared to the hardness of other
materials.
How can mineral hardness be used as a tool for
identification?
Do you think this test alone will help us
identify all of our minerals? Explain your
thinking.
Why did we not test the rocks from our
collection?