JOB DESCRIPTION: A mineralogist is a person who studies minerals. A mineral is a naturally occurring solid. The earth is made from thousands of minerals made of various elements. Rocks are composed of a variety of minerals. Mineralogists study rocks, gems and other minerals to find out more about them. Some mineralogists work for mining companies to enhance the processing of minerals from ores. Most other mineralogists work in laboratories at universities. Their findings can be used to tell us more about the environment.