Most minerals are composed of two or more elements with their atoms arranged in a regular structure, called a crystal lattice or crystal structure. In chemistry, this is known as a compound. To visualize crystal structure, think of balls attached to other balls with sticks to make regular three-dimensional patterns. The balls represent atoms and the sticks represent the forces between the atoms. Electromagnetic forces between atoms hold some chemical compounds together. In other compounds, the atoms form covalent bonds, which means they share electrons. Scientists classify many minerals into groups based on the types of atoms found in the minerals. For example, oxides consist of metallic atoms bound to oxygen atoms, and sulfides are combinations of metal and sulfur atoms.

Humans have long prized granite, an igneous rock rich in the minerals quartz and feldspar, as a building material because it does not crack easily and can be polished. The Smithsonian's National Museum of Natural History building was built out of four different types of granite from four different states on the East Coast of the United States. Other rocks that make up the building include roof tiles of slate, and museum floors made of terrazzo, which is crushed marble and granite with cement filler. Elsewhere in Washington, D.C., marble, granite, and bluestone gneiss went into the Washington Monument; marble was used inside and outside the Lincoln Memorial; and red sandstone makes up the Smithsonian Castle on the other side of the National Mall. The nearby National Archives, Department of Justice, and Internal Revenue Service buildings have limestone facades and granite foundations.