Marbles are metamorphic rocks that have been formed from pre-existing rocks by exposure to high temperatures and/or pressures.
(Marbles; are; metamorphic rocks that have been formed from pre-existing rocks by exposure to high temperatures and/or pressures) (metamorphic rocks; have been formed; from pre-existing rocks; by exposure to high temperatures and/or pressures)
Marbles metamorphic rocks
are have been formed
metamorphic rocks that have been formed from pre-existing rocks by exposure to high temperatures and/or pressures
from pre-existing rocks by exposure to high temperatures and/or pressures