Virginia is a state in the Southeastern and Mid-Atlantic regions of the United States of America that offers spectacular sceneries and varied geologic history that covers about 1.5 billion years. A rock garden was developed at the Edith J. Carrier Arboretum in Harrisonburg, VA. The rock garden at the Edith J. Carrier Arboretum is a place where rocks look as they did when they were part of an outcrop on the side of a mountain or a creek in the Shenandoah National Park. Rock slabs were collected along the existing trails of the Arboretum and classified based on the mineralogy and physiographic province. The rock garden offers a place to observe Earth materials from Virginia without potentially travelling long distances. The goal is to educate the community on the local resources and promote sustainable geotourism. This paper illustrates a method for rapid and accurate quantitative mineralogical analysis of complex mixtures using X-ray powder diffraction. Correctly classifying a fine-grained sample such as a sedimentary rock using primarily the identification of minerals in a thin section or in hand specimens could not be accurate; thus, X-ray diffraction was used to confirm hand sample analyses. The samples are mostly sedimentary rocks from the Appalachian Mountains. Three different lithological types (dolostone, limestone, and shale) play the most important role in the geological context of the Rockingham county. The mineralogical features shown in this paper provide a detailed picture of the geological significance of the resources that shape the Appalachian Mountains in the Shenandoah National Park.