Both are
indicators of the chemical composition of silicate minerals, magmas and rocks.
Mafic is
used for silicate minerals, magmas and rocks that are composed of heavier
elements, like magnesium, iron, calcium and sodium. They are dark and have high
specific gravities.
Opposite to
the this, felsic silicate minerals, magmas and rocks in their composition have
less from these heavy elements. They are composed from silicon, oxygen,
aluminium and potassium, are light in color and have lower specific gravities.
