gems, peridot, olivine, Egypt, Zabargad, St. John’s Island

An investigation by Nicolas-Louis Vauquelin of beryl from Saxony following Johann Bartholomäus Trommsdorff’s announcement that it contained a supposed new earth, which he named Agustine (Agusterde). Vauquelin chemically examined the material to determine whether this represented a genuinely new substance and found no justification for recognizing Trommsdorff’s proposed earth as a new constituent. The paper belongs to the intense late eighteenth-century effort to determine the chemical composition of minerals and identify new elements and earths. Of gemological interest, it contributed to clarification of the chemistry of beryl shortly after Vauquelin’s own discovery of glucina (beryllia) in beryl and emerald.