Earth's Layers...
Earth has a thin layer of solid rock, which is called the crust. It is believed that the crust is between 3 to 30 miles deep.
The crust is made of 2 types and varies:
The continental, which is the thicker of the 2( 25 miles or so), and it forms the land.
The oceanic, the thinner( 3 miles or so), and makes up the ocean floors.
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Under the crust layer is the mantle layer, which is about 1,800 miles thick. There is a thin layer within the mantle, called the asthenosphere. It has a small amount of molten rock, which we know as magma or lava..
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Then there is the outer core, which is about 1,400 miles thick. It is made up of liquid iron, nickel and other elements.
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Last is the inner core, that is around 800 miles thick, and about the size of the Moon. It is mostly made up of silicon, according to this video @ 2:53.
I thought it was made up of iron, but I'm no scientist so there goes that!!! LOL...
Who knows???
Oh, by the way,,, Diamonds are formed by the outrageous heat and pressure within the Earth's crust..
I Hope These Videos Were Informative!!!
Thanks For Viewing...