The first step involves determining the texture of your unknown rock sample. There are only two metamorphic rock textural types, foliated and nonfoliated. Examine your rock and CLICK on the appropriate texture to move to the next identification step.

Foliated texture. Sets of flat or wavy parallel planes that represent the preferred orientation of the minerals in the rock under a deforming pressure. The main cause of foliation is the presence of platy minerals which are easily elongated such as micas or amphibole.
Nonfoliated texture. Nonfoliated rocks will appear as massive and structureless. They exhibit a nonfoliated character because the original rocks (protolith) were composed of equant grains that tended to grow equally in all directions and form an interlocking, dense, crystalline mosaic. .