[The miraculous minerals of Michele Mercati. Natural history between medicine and the clergy in Rome in the second half of the Sixteenth century].

Many Italian scholars in the sixteenth century studied minerals. This was not only for the sake of increasing geological knowledge. Minerals, like all other natural phenomena, reflected divine order. Minerals were thought of as a broader category than the lifeless substances found beneath the crust of the earth. Stones, generated in animal and human bodies, were included among minerals, as well. The appearance of kidney stones, gall stones and bladder stones in early modern mineral collections point to the religious motives of the scholars that studied them. In this article, I will examine the mineralogical collection brought together and described by Michele Mercati (1541-1593), the so-called Metallotheca. I will map the circles of physicians, scholars and ecclesiastics in which Mercati lived and functioned. I will then investigate Mercati's descriptions of stones, grown inside animals and men. The specific connections between Mercati and the members of the Oratory of Rome, an influential religious organisation of the Sixteenth century, direct us towards a proper understanding of the significance of Mercati's minerals. Certain minerals, including stones originating in animate bodies, were thought of as approaching the supernatural. The proper attitude for the scholar of nature would then be to turn from curiosity into awe and even veneration.