Granite
is generally produced by magma solidifying under extreme pressure.
When magma rises, due to being lighter than surrounding rocks,
it begins to cool. This cooling happens slowly, and crystals
are formed beneath the surface of the earth. This produces
a tightly interlocked structure, which is why granite is such
a strong stone. It is comprised mostly of
quartz,
alkali feldspar, and plagioclase feldspar. Granite makes up
a lot of the earths crust, and is generally revealed to the
surface when continental shifts cause breaks in the landscape
that allow it to be seen.