Right answer: the amount of silica minerals in granite
The granite is a plutonic igneous rock, this means it was formed from a deep slow cooling in large masses of magma.
This rock is essentially composed of silica in high quantities, alumina, sodium and potassium oxides, quartz, alkali feldspar, plagioclase and mica.
There are granites of different colors, depending on their chemical composition, although they are generally clear due to their high amount of silica.
