The forces of weather on the surface of the Earth can change the minerals that make up rocks. When mechanical weathering processes destroy old rocks, softer silicate minerals such as olivine and plagioclase may dissolve away, leaving behind harder minerals, such as quartz. In chemical weathering, the atoms react with oxygen or water in the environment. (Think of iron exposed for several months to the water and air outdoors. The iron rusts, and rusting is a kind of chemical weathering.) In the presence of water, some minerals transform into more hydrous minerals. Other minerals, such as calcite (calcium carbonate), dissolve completely in water over time. Some silicate minerals, such as quartz and garnet, are more resistant to weathering than other silicates, such as feldspar and mica.

Minerals can be opaque, meaning they block all light from passing through them; translucent, meaning they block some of the light; or transparent, meaning they pass most or all the light. A typical garnet or amethyst crystal is translucent; if you hold it up to a bright light, only a small fraction of the light entering the crystal ever reaches your eye, and you cannot see clear images through the crystal. Mica, a silicate mineral, can be cut into thin sheets so transparent that they serve as panes of a window. One colorless, transparent variety of calcite, dubbed "Iceland spar," exhibits a phenomenon called double refraction, which makes one object look like two. Another mineral, a borate called ulexite, occurs in thin parallel fibers that conduct light through them by total internal reflection, just like manufactured optical fibers. Ulexite seems to project an image onto the polished surface of the mineral, giving it the nickname "television stone."

Many building materials - concrete, tiles, brick, glass, paint, plaster, and drywall - contain rocks or components derived from minerals. Quarries, or open-pit mines, produce crushed rocks, gravel, and sand of different grain sizes, known as aggregates. Coarsely crushed rocks and gravel are mixed with cement, a binding material that holds the aggregate in place to form concrete. The ancient Romans invented concrete, but after their empire fell, concrete technology was forgotten until the 18th century. Limestone, a sedimentary rock, and gypsum, a mineral in sedimentary deposits, are two key ingredients of cement. Sand and smaller particles of crushed rock go into making bricks. Finely ground gypsum is filler in paint, plaster, and drywall. While different types of glass used in buildings may have specialized ingredients and coatings, they are all mostly silica, or melted quartz sand.