Georgius Agricola systematized the study of rocks, minerals and fossils, creating a standard classification and naming system that had not existed before. Perhaps more than any other individual, Agricola is credited with the scientific study of geology through his personal observation and scholarly research.
Georgius Agricola worked as a physician, but his passion was the study of rocks. Living in a mining district, he penned "De Re Metallica," which was a scientific inquiry into the search for and extraction of ores. The book rejected divining and dousing as methods for finding ores and became the standard text for the mining industry for the next 200 years. Agricola also wrote up his observations of the geologic column, describing the way distinct layers of rock seemed to be laid down on top of one another. This work was foundational to the later work of Charles Lyell and the gradualists. Agricola developed a systematic method for classifying minerals according to their physical properties, rather than by their alleged use in alchemy, and he even found time to write a treatise on fossils that would not be surpassed until the work of Robert Hooke over a century later. He is also among the first scientists to have described the erosive action of wind and water.