what are rocks made of? minerals are not made by people; they are … …naturally occurring...
TRANSCRIPT
What are rocks made of?
Minerals are not made by people; they are …
…naturally occurring substances.
Name four properties (or clues) that scientists use to identify minerals.
Color, luster, streak, and hardness
Which property means the way the light bounces off the mineral?
What words can be used to describe a mineral’s luster?
Glassy, dull, shiny, greasy
Why is color not a good property to use to identify a mineral?
Many minerals have the same color.
slate limestone
What are three testers that can be used to determine a mineral’s hardness?
fingernail, penny, nail
What type of rock is formed when magma cools and hardens?
There are two types of Igneous rocks
Intrusive in side the earthExtrusive out side the earth
Granite is an example of an Intrusive Igneous Rock
It forms under the Earths surface from the cooling of magma
Intrusive igneous are usually rough to the touch unless they are polished
Examples: Kitchen CountersThe Continental Crust of the Earth
is primarily made of Granite
Other examples of Intrusive Igneous Rocks:
Gabbro Andesite Diorite
Examples of Extrusive Igneous Rocks
• Basalt is an example of an Extrusive Igneous Rock
• The Oceanic Crust is made primarily of Basalt – Basalt is formed from lava
on the crust of the Earth. – Because it is formed on the
surface, the crystals are very fine-grained
Other examples of Extrusive Igneous Rocks
Obsidian Rhyolite Scoria
What type of rock is formed when weathering and erosion cause sediments to press together in layers?
Sedimentary RocksSedimentary rocks are formed by the
accumulation of sediments.
Sediments include materials from sand grain size to boulder size
Clastic Sedimentary Rocks
• Clastic Sedimentary Rocks are formed from mechanical weathering debris
• Mechanical weathering takes place when rocks are broken down without any change in the chemical nature of the rocks
Breccia Conglomerate
Sandstone Shale
Chemical Sedimentary Rocks
• Chemical Sedimentary Rocks form when dissolved materials precipitate from solution
Halite
Limestone
Organic Sedimentary Rocks
• Organic Sedimentary Rocks form from the dead plants and animals and their debris.
• Coal and fossiliferous limestone are examples of organic sed. Rock
Fossiliferous Limestone
Coal
What type of rock is formed when change occurs from heat and pressure in the Earth?
Metamorphic Rocks Metamorphic rocks have been modified (changed) by
heat, pressure and chemical process
usually while buried deep below Earth's surface.
There are two basic types of metamorphic rocks: Non-foliated Foliated
Foliated Metamorphic Rocks
• Foliated metamorphic rocks: have a layered or banded appearance known as a foliation
Gneiss
Schist Slate
Non-Foliated Metamorphic Rock
• Non-foliated metamorphic rocks such as marble and quartzite
• do not have a layered or banded appearance
Melted rock below the Earth’s surface is called…
Small bits and pieces of rocks are called…
The breaking down and wearing away of rocks is called…
The movement of sediments from one place to another is called…