Transcript of Earth’s Resources Chapter Four. Lesson One: Minerals & Rocks Objectives Compare and contrast...
- Slide 1
- Earths Resources Chapter Four
- Slide 2
- Lesson One: Minerals & Rocks Objectives Compare and
contrast properties of minerals. Describe how three main kinds of
rocks form. Read Science books page 202 & do review page
203
- Slide 3
- Minerals and Rocks Vocabulary: Lesson 1 Luster- The property of
a mineral that describes how light reflects from the mineral.
Sediment- Tiny bits of animals, plants, or weathered rock. Mineral-
A solid, nonliving substance found in nature. Sedimentary Rock-
formed when layers of sediment pile up and are pressed together.
Metamorphic Rock- Formed deep inside the Earth. Heated and squeezed
by the weight of rocks above. Igneous Rock- Formed when melted rock
is cooled and hardened either inside Earth or on Earths
surface.
- Slide 4
- What are minerals? A mineral is a solid, nonliving substance
found in nature. Salt, gold, and iron are minerals. The graphite in
your pencil is a mineral!!! Minerals are the building blocks of
rocks. Minerals are found underground and in soil. They are even in
the ocean and on the ocean floor. There are more than 3,000
different kinds of minerals. Each mineral has its own properties.
You can use the properties of minerals to tell them apart.
- Slide 5
- Color Turquoise FeldsparQuartz It is easy to observe a minerals
color. Most minerals come in just one color. However, some, like
quartz, come in many colors. Some, like gold and pyrite, are the
same color. You cannot use color alone to identify a mineral.
- Slide 6
- Streak Streak is another property used to identify minerals.
Streak is the color of the powder left when a mineral is rubbed
across a white tile. A minerals streak may or may not be the same
as the minerals color.
- Slide 7
- Luster Luster describes how light bounces off a mineral. Some
minerals are shiny like metal. Others are not. Luster is another
property used to identify a mineral.
- Slide 8
- Hardness The hardness of a mineral describes how easily it can
be scratched. Some minerals, like talc and gypsum, are soft. They
can be scratched with a fingernail. Other minerals, like quartz,
are much harder. Not even a steel file can scratch quartz.
- Slide 9
- Pyrite may look like gold, but its streak is different. Pyrites
streak is greenish- black. Golds streak is yellow. Mica can have a
pearly luster. Diamond is the hardest mineral. No other mineral or
object can scratch it.
- Slide 10
- How can hardness be used to identify minerals? Mohs hardness
scale shows the hardness of a few common minerals. There are many
more minerals for each level of hardness. Diamond, 10 on the scale,
is the hardest mineral. Talc, 1 on the scale, is one of the softest
minerals. Minerals with higher numbers can scratch minerals with
lower numbers. For example, quartz can scratch any mineral with a
hardness that is less than 7. Quartz, however, can itself be
scratched by a mineral with a hardness that is greater than 7.
- Slide 11
- What are rocks? A rock is a nonliving material made of one or
more minerals. There are hundreds of different types of rocks. Some
rocks, like granite, are made of several minerals. Some rocks, like
limestone, are made mostly of one mineral. A rocks color gives
clues about the minerals that make it up.
- Slide 12
- Grains Rocks are made of mineral pieces called grains. To a
person who studies rocks, a rocks texture is how its grains look.
Some rocks have large grains you can easily see. These rocks have a
coarse texture. Some rocks have grains that are too small to see.
These rocks have a fine texture.
- Slide 13
- Igneous Rocks Rocks are classified by how they form. There are
three kinds of rocks-igneous, sedimentary, and metamorphic. An
igneous rock forms when melted rock cools and hardens. Inside
Earth, melted rock called magma cools and hardens very slowly. A
rock with large mineral grains forms. Melted rock that flows onto
Earths surface is called lava. Lava cools and hardens quickly. A
rock with small mineral grains forms.
- Slide 14
- Slide 15
- What are sedimentary and metamorphic rocks? Sediment is tiny
bits of weathered rock or once-living animals or plants.
Sedimentary rock is a kind of rock that forms from layers of
sediment. Sedimentary rocks form where weathered and eroded
materials are dropped. This often happens at the bottom of rivers,
lakes, and oceans. Over time, sediment piles up. The top layers
press on layers below. In time the sediment becomes cemented
together and forms rock.
- Slide 16
- What are sedimentary and metamorphic rocks? A rock that has
been changed by heating and squeezing is a metamorphic rock. Deep
inside Earth, rocks heat up and bake. They also get squeezed by the
weight of the rocks above them. All this heating and squeezing can
cause a rocks minerals to change into new minerals. A new rock
forms with properties that are different from the original
rock.
- Slide 17
- Shale is a sedimentary rock made up of bits of weathered
materials. Fossils are often found in the sedimentary rock
limestone. Limestone can form from the remains of once- living
things. Sandstone is sedimentary rock that forms from tiny
particles of sand. Gneiss is a metamorphic rock. It forms from
granite. Slate is a metamorphic rock. It forms from shale. Phyllite
is a metamorphic rock. It forms from the metamorphic rock
slate.