Download Introduction to Rocks Aim: How can I identify an Igneous Rock?

Aim: How can I identify an Igneous Rock?
Rock vs. Mineral

 Mineral- a pure substance found on Earth (element),
that occurs in nature (non man-made), that is
inorganic (non-living).
 Rock- made of one or more minerals mixed together
with different materials, which can include dirt,
other rocks, sands, fossils, etc.
Monomineralic or Polymineralic

 If a rock contains only one mineral it is called:
 Monomineralic
 If a rock is made up of more than one mineral it is
called:
 Polymineralic
How do we determine the
different types of Rocks?

Rocks get classified according to their origin-How and
where they were formed. There are three main
categories.
Three Categories

 Igneous- formed when molten rock cools and
solidifies.
 Sedimentary-the result of compaction and
cementing of layers of sediment.
 Metamorphic- formed from heat and pressure.
Igneous Rocks

 Today we are going to focus primarily on one type of
rocks, Igneous Rocks. When we talk about Igneous
Rocks they always form by melting and
solidification.
 So most Igneous rocks form at or near a volcano.
Identifying the Parts

 Using the following words: volcano, lava, magma fill
in the spaces below.
LAVA
VOLCANO
MAGMA
Unique Info

Igneous Rocks are the ONLY rock made from a liquid.
When liquid cools it solidifies and crystallization occurs.
How Igneous Rocks Form

Lets see!
Intrusive

 If the Igneous rock forms inside the volcano we call
it:
 Intrusive
 The rock will have large crystals so we can
determine that it took a
 long time to cool.
 Since this rock formed inside of the volcano, it
formed from
 Magma
Extrusive

 If the Igneous rock forms at the surface of the volcano we
call it
 Extrusive.
 It will have very small or no crystals, so now we can
determine that it took a
 Short time to cool.
 Since this type of igneous rock formed at the surface, it
formed from
 Lava