Brenizer

Here we have a marker which is very different from anything you’ve already seen on the tour to this point. This is a new type of rock called a metamorphic rock. Metamorphic rocks are commonly used for cemetery markers as well as kitchen countertops and floor tiles. This marker is made from a rock called gneiss (pronounced “nice”). (Image 2)

To understand how a metamorphic rock forms, we need to discuss the rock cycle. The rock cycle explains how different types of rocks form and change over time. When rocks are exposed at the Earth’s surface, they are broken down into sediments by the process of weathering. These sediments are commonly carried away by the process of erosion and deposited somewhere else, usually in a body of water like the ocean. As these layers of sediment pile up, they become cemented together through the process of lithification, forming a sedimentary rock. (Image 3)

Most sedimentary rocks are generally not suitable for use as grave markers, either because they are weak or hard to carve cleanly. However, if a rock gets buried deep in the Earth, it can undergo a transformation called metamorphism. Metamorphism takes one type of rock and slowly changes it into a new rock with different properties. Commonly, these new metamorphic rocks are both denser and stronger than the original rock. This makes metamorphic rocks suitable for cemetery monuments. Although they aren’t common in Parsons, some of the prettiest markers are made of gneiss, which you will see later in the tour.