Granite is a common type of felsic intrusive igneous rock that is granular and phaneritic in texture. Granites can be predominantly white, pink, or gray in color, depending on their mineralogy. The word "granite" comes from the Latin granum, a grain, in reference to the coarse-grained structure of such a holocrystalline rock. By definition, granite is an igneous rock with at least 20% quartz and up to 65% alkali feldspar by volume. Wikipedia, Granite

Keely stood, fourteen years ago, on the wrong side of the abyss which separates conjecture from fact. "The bridge of mist" he writes, "which spanned the chasm between the two is gradually resolving itself into one of granite, which the nations of the earth may safely traverse, stretching between the two centers; the celestial and terrestrial. The visible one is the one of mist: the invisible one is the one of granite." [from Keely and His Discoveries]