  Albert’s Treatise on Minerals (De mineralibus) shows that he undertakes his own observations and did not merely collate authorities on the topic. He studies different kinds of minerals and metals as well as rare stones. Beginning with the mineral kingdom, he notes the properties of each mineral specimen, including where it was found along with its cause or causes. Next, he deals with rare stones, investigating the powers of these specimens along with their causes. He then produces an alphabetical list of a large number of these more precious stones. Throughout the treatise, Albert is careful always to proceed from the effects or properties of the mineral world to hypotheses concerning their causes. It is clear from his text that he himself made a number of studies (experiments) with different minerals.