These rocks are formed by subjecting any rock type – sedimentary rock, igneous rock or another
older metamorphic rock to different temperature and pressure conditions than those in which the original rock was formed.
This process is called metamorphism meaning to “Change in form”. The result is profound change in physical properties and chemistry of the stone. The temperature and pressure
required for this process are always higher than those found at the earth’s surface.
Metamorphosed form of Igneous Rocks –
(1) Granite – Gneiss
(2) Basalt – Schist
(3) Basalt – Amphibolite
Metamorphosed form of Sedimentary Rocks -
(1) Shale – Slate
(2) Limestone – Marble
(3) Chalk and Dolomite – Marble
(4) Sandstone – Quartzite
(5) Conglomerate - Quartzite
Metamorphosed form of Metamorphic Rocks –
(1) Slate – Phyllite
(2) Phyllite – Schist
(3) Gabbro – Serpentinite
