Natural Stone ..Granite Chemical Composition

Granitic is coarse-grained structure formed from magma that slowly cooled and solidified underground over several millions of years. Granite mainly consist of feldspar (mainly K, Na, Ca, Al Oxides), quartz (Si Oxides), mica (mainly Si, Al Oxides), and amphibole minerals (Si Oxides with Mg).

Compressive strength estimate: 29,000 psi
Melting temperature 1215–1260 °C (2219–2300 °F)

A worldwide average of the chemical composition of granite, by weight percent (over 2,000 analyses):
SiO2 72.04% (silica)
Al2O3 14.42% (alumina)
K2O 4.12%
Na2O 3.69%
CaO 1.82%
FeO 1.68%
Fe2O3 1.22%
MgO 0.71%
TiO2 0.30%
P2O5 0.12%
MnO 0.05%

See wikipedia.org/wiki/Granite for much more detail