Metamorphic rock is the result of the transformation of a pre-existing rock type, the protolith, in a process called metamorphism, which means "change in form". The protolith is subjected to heat and ...

There are three types of rock found on Earth. These are igneous, metamorphic and sedimentary. Each rock type is formed in a different way. For example, the rock malachite is mostly made of the ...

A RICH store of observations especially on the metamorphic rocks of Great Britain, numerous excellent drawings of rock sections as seen in the microscope and admirable clarity of statement are the ...