Transcript How can we identify a mineral or a rock?

How can we identify a
mineral or a rock?
GPS S3E1b. Recognize the physical attributes of
rocks and minerals using observation, measurement,
and simple tests
.
…by its hardness
Talc is the softest mineral.
Diamond is the hardest mineral.
Let’s do the hardness or scratch test!
• You will need: your fingernail, a penny, a
concrete nail, different kinds of minerals, and the
Mohs Scale of Hardness chart below.
Bring out your rock and test its
hardness by doing the scratch test!
…BY ITS COLOR
This is the mineral talc.
This rock called granite has 3 colors
which means it has 3 kinds of minerals.
But wait!!!
• We cannot identify all rocks and minerals
just by looking at their color/s.
• Why? Can you tell which is gold and which is
pyrite (fools gold)?
So we need the other properties of
minerals to help us identify them.
• Streak is another property. It is the
color of the fine powder produced
when a mineral is rubbed against a
hard surface.
Do your own streak test using
your pet rock.
…another property of mineral is luster.
• Luster describes how light bounces off
(reflects) a mineral.
• Which is metallic and shiny and which is dull?
The texture or the “feel” of a mineral
depends on the size of its particles.
This mineral has very
tiny particles. It has a
smooth texture.
This mineral has big
particles. It has a
rough texture.
The way to identify rocks and minerals
is learning about their properties:
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Color
Streak
Hardness
Luster
Texture
Let’s Review!
• Read pp. 124 and 125 of your book. Use the
pictures to help you understand what you
read.
Now it’s your turn to identify your
rock!
• Adopt a pet rock.
• Fill out the chart. Make your
pet rock “look good” by
following the rubric.
Rubric for your pet rock
4 Points (100%)
3 Points (75%)
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