How is marble formed?
Marble comes from limestone that has been changed by heat and pressure.
The rock we call marble is really made-over limestone – it is a metamorphic rock. That is, it began as one kind of rock and later changed into another kind.
Ages ago the skeletons and shells of countless billions of tiny sea creatures were pressed together under the sea to form a rock called limestone. Great heat and pressure deep within the earth slowly changed the limestone rock into marble.
Marble is one of our most beautiful and useful rocks. It is often used in building and is easily carved for statues. Marble can be of many different colors.
Pieces of marble big enough to use in building must be dug out of the ground. Digging such rocks our of the ground is called “quarrying.”
When marble is quarried, a machine called a “channeler” frees blocks of marble by cutting deep channels or slots in the face of the rock. The blocks are lifted out by large derricks. – Dick Rogers