Metamorphic

[Sarah]

Pertaining to, produced by, or exhibiting, certain changeswhich minerals or rocks may have undergone since their originaldeposition; -- especially applied to the recrystallization whichsedimentary rocks have undergone through the influence of heat andpressure, after which they are called metamorphic rocks.

[Little_Girl]

Denoting or relating to rock that has undergone transformation by heat, pressure, or other natural agencies, e.g. in the folding of strata or the nearby intrusion of igneous rocks.

[Tanya Shivari]

(of rock) changed into a new form and structure by very great heat and pressure: