Granite is an igneous rock. It is formed as a result of the
slow crystallization of molten magma at great depths in the
earth's crust. Over millions of years, uplift and erosion
have resulted in granite outcroppings at the surface. The
minerals which make up granite are generally quartz, feldspar
and various mafic minerals (amphiboles, pyroxenes, micas and
secondary materials). It is the size, distribution and precise
chemistry of these minerals which give the granite it's colour.
The silica content of granite should be at least 70%. Due
to the extreme density of granite, a cubic foot weighs 200
the stone industry, "granite" is a term applied
to almost all igneous rocks and schists. Traditionally any
very hard crystalline rock (quartz-based as opposed to marble,
calcite-based) which possesses the following characteristics
would be called granite:
apparent natural jointing
Difficult to work without special tools.
Takes a high polish
Extremely resistant to natural weathering
can be worked to achieve every type of finish from traditional
hand tooled, flame textured, shot blasted, acid washed, or
honed to highly polished mirror finishes.