gems, minerals, mineral collecting, Naldi

An alphabetically arranged mineralogical and oryctological dictionary covering what eighteenth-century authors broadly termed “fossils,” meaning substances dug from the earth rather than fossils in the modern restricted sense. Entries include earths, sands, salts, sulphurs, bitumens, simple and compound stones, common and precious stones, transparent and opaque minerals, metals, and petrified remains of plants and animals. Bertrand discusses their names, descriptions, occurrence, formation, origins, properties, and uses, drawing together contemporary mineralogical and natural-historical literature. Gemological material is dispersed throughout the dictionary under individual stones and mineral substances, making the work useful for tracing eighteenth-century terminology and contemporary ideas concerning precious stones, crystal form, mineral classification, and the relationship between gems and the broader mineral kingdom.