A common instrument used to study thin sections of rock, mineral, and soil samples is a petrographic microscope.
(A common instrument; used; to study thin sections of rock, mineral, and soil samples) (A common instrument used to study thin sections of rock, mineral, and soil samples; is; a petrographic microscope)
A common instrument A common instrument used to study thin sections of rock, mineral, and soil samples
used is
to study thin sections of rock, mineral, and soil samples
a petrographic microscope