It is what it says it is - a dictionary of jewellery with many illustrations and examples of the various jewellery. It gives a summary of each subject, both obscure and common day terms with references to a variety of pieces of jewellery, their origins, other references and books to read to gain more in depth knowledge. It provides definitions and descriptions, biography details on designers and makers throughout history. I used this as a reference for JET2 particularly and was extremely useful in identifying uncommon material.