Eisco Quartzite Specimen (Metamorphic Rock), Approx. 1″ (3cm)

Applying significant pressure to sandstone results in the formation of quartzite. Because of its durable nature, quartzite is often used in paleoclimate studies to measure the extent and timing of glaciation. In the classroom, quartzite is useful alongside sandstone as a comparison between rock types, or in more general metamorphic classification exercises.