Mineral specimens found in historical collections often include specimen labels, which may provide vital information on the nature, chemistry and origin of the material. However, the evolution of chemical notation, particularly during the eighteenth and nineteenth centuries, led to a wide range of ways in which a given sample could be adequately documented, many of which may still be found in collections in the present day. Prior to the advent of modern mineralogy, samples were labelled using a complex and sometimes baffling language of alchemical symbols with little meaning to modern scientists. The efforts of notable chemists and mineralogists, such as Torbern Bergman, Antoine Lavoisier, John Dalton and Jöns Jacob Berzelius, began to reform and unify chemical nomenclature, providing a number of new terms, symbols and approaches to the description of materials. With the advent of atomic theory in the nineteenth century, new classification schemes based on quantitatively describing the atomic arrangement and composition of minerals were proposed, representing a significant step towards modern mineralogy. Understanding the development of chemical notation over time not only facilitates the identification of mineral specimens but may also provide clues as to the date that the sample was documented, and potentially even the location.