Look up tour de force in Wiktionary, the free dictionary. Tour de Force may refer to: 1  French phrase, meaning, a feat or display of strength, skill, or ingenuity, such as the funny movie is a comic tour de force.  Tour De Force (tour), 1986 Elton John Concert Tour.
Granite is an igneous rock composed of mostly two minerals: quartz and feldspar. It is an intrusive rock, meaning that it crystallized from magma that cooled far below the earth's surface.
Excluding the rocks between my ears, I'd have to say that basalt and granite have the honor of being the most important rocks in the crust. Basalt and granite actually have quite a bit in common. Both are igneous rocks, which means that they cooled from a magma (the earth gets very hot just below the surface, and there is lots of liquid rock available). Both are made up of minerals from the silicate group, so both have large amounts of silicon and oxygen.