Classification of Metamorphic rocks

In order to identify any metamorphic rock, it is first necessary to determine its texture. The texture of a metamorphic rock is both a description of its constituent minerals along with their arrangement and size. Typically this will be initially described as foliated or non foliated. Foliation is the existence or appearance of layers. Non foliated textures have no obvious features and are classified mainly on the basis of crystal size.

Metamorphic rocks are classified based on their texture and mineralogical composition. This information will also be useful in determining the conditions under which the rock has formed, which can give valuable insight into the geologic past.

To begin identifying your metamorphic rock choose the appropriate texture from the menu on the left.