gems, encyclopedia, lapidaries, minerals, early gemology, early mineralogy

A major medieval vernacular encyclopedia by the Florentine statesman and scholar Brunetto Latini (ca. 1220–1294), Li livres dou tresor was composed in Old French during Latini’s exile in France in the 1260s. Organized in three books, it assembles a broad compendium of contemporary knowledge: the first treats theology, universal history, geography, astronomy, natural history, animals, plants, stones, and other aspects of the physical world; the second concerns ethics, virtues, and vices, drawing particularly upon Aristotle; and the third addresses rhetoric, politics, and the government of cities. Of particular gemological interest are the sections dealing with minerals and precious stones, which preserve medieval European conceptions of their names, characteristics, origins, and reputed properties. The work circulated extensively in manuscript and was translated into several European languages, making it an important source for the transmission of natural-history and lapidary traditions in the later Middle Ages.