Wk 14 – 20/8
Science Grade 6
Rocks and Minerals
What are these?
They are minerals.
Minerals are the building blocks of rocks.
 They are not alive, and not made from anything that was once living.
 They are natural, not made by man.
 They are made from elements – maybe one or more.
 The same mineral will always be the same.
 They are solid crystals.
Gypsum is usually a white
colour and quite dull. It is a
very soft mineral that can be
scratched with a fingernail.
Topaz can be blue, yellow or
red and looks glassy. It is
nearly as hard as a diamond.
Fluorite can be white, yellow,
green or blue and looks glassy. It
is fairly soft but harder than your
finger nail.
Compare and contrast
Use the above information to fill in the table below.
minerals
Gypsum
Topaz
Fluorite
colour
fluorescence
hardness
Choose one type of rock each. Read it carefully, looking for how it is made,
and what it might look like. Be ready to compare it to other types of rock.
Igneous rock
One type of rock, formed when melted rock hardens, is called igneous rock.
This rock forms when melted rock, magma, gets pushed up from the mantle
to the crust. The cooler temperatures in the crust cause the magma to
harden into rock.
When magma cools slowly, crystals form which makes the rock feel rough.
It may have bubbles that pop and leave holes in the rock. When the magma
comes out of the crust, as lava, it cool quickly. These rocks are not rough,
but smooth and may even be shiny.
How is it made?
Write and draw a picture.
What does it look like?
Stick on some pictures of igneous rock.
Sedimentary rock
Sedimentary rock is much more likely to be found on the Earth's surface,
than underground. Sedimentary rock forms when layers of sediment – bits
of rock that have been weathered, settle over time and join together.
If you look at a rock, and can see separate layers of sand or rock, or can
see fossils, you are probably looking at a sedimentary rock.
How is it made?
Write and draw a picture.
What does it look like?
Stick on some pictures of igneous rock.
Metamorphic rock
The word metamorphic comes from the word meta, which means 'change'.
Metamorphic rock is made from igneous or sedimentary rock that has been
changed by heat and pressure. Metamorphic rock can form deep in the
Earth from the pressure above, or where plates press together. Heat
either comes from deep inside the Earth, or from magma or lava.
Metamorphic rocks often have ribbon like layers. You can see that these
layers have been pushed together with lots of pressure to become one rock.
Crystals are often very clear on metamorphic rocks.
How is it made?
Write and draw a picture.
What does it look like?
Stick on some pictures of igneous rock.
Discuss with other people in the class.
What is similar, and what is different with the 3 types of rocks.
Discuss how they are made and what they look like.
Record one main difference about how they are made,
And one main difference about what they look like.
Draw conclusions
Why are fossils not found in igneous rocks?
My Dictionary
minerals: _________________________________________
igneous rock: ______________________________________
metamorphic rock:___________________________________
sedimentary rock:____________________________________
Homework
If we could no longer use the words 'metamorphic', 'igneous' and
'sedimentary', what could we use instead?