Igneous Rock
Obsidian
a sharp, glasslike volcanic rock
Pumice
a volcanic rock that is a light, sponge-like rock usually found at the surface of a lava flow with a mass of gas bubbles
Where is igneous rock formed
above and below the earth
Why are igneous rocks different
because of how they are made (composition) and how fast they are cooled (texture)
what happens when it takes longer for magma to cool
less time crystals have to form, creates larger crystals and a more coarse texture
Igneous Rock
Rock formed from cooling magma and lava
What happens when magma cools quickly
small or no crystals --> fine texture
Vesicular
spongy appearance, air pockets or bubbles trapped in rock due to rapid cooling (extrusive)
Igneous rock forms
when magma (hot liquid, rock) cools and solidifies
When does extrusive igneous rock form
when magma erupts onto earth's surface through a volcano or fissure (cracks in earths crus) and cools quickly
When does intrusive igneous rock form
when magma pushes into surrounding rock below the earths surface and slowly cools
Basalt
A fine grained igneous rock that is mafic
Rhyolite
An extrusive igneous rock that is felsic
Mineral
An inorganic solid with a definite chemical composition and crystalline structure.
Granite
An intrusive igneous rock that is felsic
Fine Grained Igneous Rock
Fast cooling magma in extrusive rock
Slow cooling magma
Forms large coarse grained crystals
Fast cooling lava
Forms small fine grained crystals
Mafic
Igneous Rock containing large amounts of Iron and Magnesium, dark in color and high in density
Felsic
Igneous rock containing large amounts of aluminum and silicon, low density and light color
Glassy Texture
Igneous rocks consisting of material that cooled too quickly for crystals to form.
What happens when magma cools very slowly
LARGER crystals --> coarse texture
Magma
Molten rock found below ground.
Lava
Molten rock that is found above ground.
Course Grained Igneous Rock
Slow cooling intrusive rock
fast cooling magma
finer texture
What does the texture of the ingenous rock depend on?
how fast magma cooled
Magma
is a complex mixture of melted minerals, not all minerals melt of freeze (Solidify) and the same temperature
Intrusive Igneous Rock
rock formed from the cooling and solidification of magma beneath Earth's surface
Extrusive Igneous Rock
rock that forms from the cooling and solidification of lava at Earth's surface
