Examples of them are marble, quartzite, and slate.  
Lesser-known ways to form them include metasomatism, retrograde, and hydrothermal.  Mineral and textural changes are characteristic when they form. The regional varieties occur in the roots of mountain ranges. Foliation is usually the first aspect evaluated when they are categorized. The contact method of producing them are found in aureoles. Examples of them are marble, quartzite, and slate.  For 10 points, name this type of rock, examples of which include marble, quartzite and slate, which are sedimentary or igneous rocks that have been changed by heat and/or pressure.
Lesser-known ways to form them include metasomatism, retrograde, and hydrothermal.  
{metamorphic} rock