A
what is magma?
its a layer of melted rock
what is the definition of igneous rocks?
they're rocks that are formed from melted rock.
what is lava?
it is Magma that reaches the Earth's surface.
what two types of igneous rocks are there?
Intrusive and Extrusive Igneous rocks
what are minerals?
natural, nonliving substances that make up rocks
Extrusive Igneous rocks form where?
Outside of Earth's surface
Intrusive igneous rocks form where?
inside/under Earth's surface
Pumice is also known as what?
Lava rock
Why does pumice have tiny holes?
the tiny holes are caused by gases that escape as the lava is cooling (so as the lava is cooling/forming into a rock there's gases escaping)
each mineral has a certain what?
crystal shape
Do intrusive igneous rocks cool quickly or slowly?
slowly
do extrusive igneous rocks cool quickly or slowly?
quickly
Give me two properties of Pumice?
it is lightweight
has tiny holes
its often crumbly
rough texture (good for exfoliating/scrubbing off dirt)
How can we tell if rock cools slowly or quickly?
if a rock cools slowly, it has larger mineral crystals
if it cools quickly, it has small mineral crystals
what is luster?
it describes the way light reflects off the surface of a mineral
which igneous rock looks like black shiny glass and what type of igneous rock is it?
Obsidian/ extrusive igneous rock
what size mineral crystals does Granite have?
Large
If lava cools in a few hours, what will the size of the crystals be?
Small
what is a strong igneous rock that is commonly used in homes? *hint: kitchen*
Granite (countertops)
What is Moh's hardness scale?
it shows the hardness of a few common minerals
what do we use some igneous rocks for?
Granite- used to make buildings, roads, homes, schools (strong and long lasting)
Magma may reach Earth's surface in 2 ways, tell me what those two ways are.
it can ooze out as lava
or it can explode out as lava
Do you think that pumice can be used to make buildings? Explain why or why not
NO because Pumice absorbs water and crumbles easily
Predict: You find an igneous rock, it has no visible mineral crystals. Which type of igneous rock is it?
Extrusive
(because it didn't have time to make huge crystals big enough to be seen)
What level is a penny on Moh's hardness scale?
3.0