It formed when the sedimentary rock sandstone was changed by extreme heat and pressure into a metamorphic rock.
(It; formed; T:when the sedimentary rock sandstone was changed by extreme heat and pressure into a metamorphic rock) (the sedimentary rock sandstone; was changed; by extreme heat and pressure; into a metamorphic rock)
It the sedimentary rock sandstone
formed was changed
T:when the sedimentary rock sandstone was changed by extreme heat and pressure into a metamorphic rock
by extreme heat and pressure into a metamorphic rock