Hello I am Tessa. Welcome to FunScienceDemos. Today the big idea is rocks, and how they are formed. We
know that all rocks are made from minerals. Today I am going to show you a cool demonstration about
how rocks are formed. Rocks are made from minerals. We have to start our demonstration
with my minerals. Let us take a closer look at this first type of rock. When I look at it, I see layers
going through it, so let us try to make a rock with layers. I have here little bits of crayon
that represent minerals and rocks, and sediment. These layers are going to pile up at the bottom of oceans,
and at the bottom of lakes, and they are going to pile up on top of each other, and they are going to get
mixed up and and they are going to just keep piling, kind of like a layer cake. I make myself a little layer
cake here, and as they pile, slowly, they become this type of rock. when you look closely, I see
my layers, I see my minerals, I see my sediment... I see them all on top of each other at the bottom
of the ocean. This first type of rock is formed from layers of sediment, it is called a sedimentary
rock. Sediment, sedimentary... perfect. Rock type number two: well here is an example of rock type
number two - and if I look closely at it I still see some layers, but it is no longer a sedimentary rock,
because more change has happened to it. When I look at my model of a sedimentary rock, and I start
changing my sedimentary rock, I am going to apply some pressure, and I am going to use my hand
to apply that pressure, and I am going to press. My hands naturally have a little bit of heat, so
not only am I applying pressure, but I am applying heat, and this heat, and this pressure is causing
my sedimentary rock to change. This new type of rock is called a metamorphic rock. Metamorphic
means changed. I have applied heat and pressure to my rock, now I have a metamorphic rock. The next
type of rock is formed from liquid rock. But, how do I get liquid rock? Well, I can change a solid
to a liquid with heat. This happens deep inside the Earth. I am going to use this hot plate to show
you, if I put my metamorphic rock and apply heat, it is going to begin to melt. It is going to begin
to melt very quickly, for my model. In real life this takes a long time. This change happens deep
inside the Earth. This liquid rock we have given a special name. It is called magma. We are watching
the change in the color, the change in the texture, the entire thing is almost changed. Those colors
are really mixing. I now have magma. I have given my liquid rock, also called magma, some time to
cool. I look at it. it is going to be a little bit different than a liquid. It is now a solid.
It is a rock - this type of rock is called an igneous rock. here is an igneous rock. Pretty
cool! Let us review: layers of sediment built up under the ocean - sedimentary rock. Rock
changed from heat and pressure - metamorphic rock. Liquid rock cooled -igneous rock. Rocks
are formed through this process called the rock cycle. If you would like to learn
more about the rock cycle, check out the links in the video description. Science is so cool!