Scientific interest in gems dates to early antiquity, with some form of systematic classification needed for considerations both practical and metaphysical. All the accumulated knowledge about gems and the lapidary arts in the ancient world was recorded in lexical lists, poems, geographies, itineraries, recipe books, and lapidaries. Many works produced in antiquity were lost in antiquity. Some are known only by reference or paraphrasing by near contemporaries or later ancient writers. Others survive only in translation, often based on secondary or more distant sources. Until gemology emerged as a geoscience in the 19th century, ancient sources were regarded as foundational documents on the subject of gem science and lapidary technology. The most influential classical author was Pliny the Elder, the first century Roman naturalist. The last volume of his Natural Historywas devoted to gems. Beginning in the Renaissance and continuing into the 20th century, many translations of Natural Historywere produced and widely distributed.

Few readers, even mineralogists and gemologists, appreciate the philological problems of literature on gem minerals in translation, especially when an original source manuscript is lost. Pliny the Elder’s opus is an instructive example. Other problems are attributable to the bias or limitations of copyists and translators. Some issues that affect the reliability of ancient gem literature in translation are discussed. Consulting independent references such as archaeological and historical literature may improve the rendering of a text, while gemological characterization of the extant corpus of gems can provide an empirical standard for comparison.

Gems were subtle goods in renaissance Italy. They were difficult to appraise for several reasons: their origins were obscure; mineral taxonomy was loose; and there were artificial gems on the market. Extreme pressure was put on assessing gems visually (without microscopes or quantitative criteria), and trust had to be placed in individuals who declared gems’ provenance and worth. Discernment was complicated by glass innovations that intensified resemblance between glass and gemstones by way of color and translucency. The newly refined glasses were generated at Venice and became known among consumers in Florence, a commerce-rich venue where it was familiar to identify the materials of moveable goods and assign value to them. There was no such person as a gemologist, but a number of occupations carried presumptive expertise. They were bankers, merchants, and jewelers, in addition to scholars who gleaned knowledge on gems and glass from texts composed in antiquity and the middle ages.

This paper examines different fields in which glass and gems were jointly studied in Florence ca. 1450-1550: commercial markets, collecting, and natural philosophy. It compares observations and values ascribed to the materials. It synthesizes research showing that glass manufacture was complex and highly regarded. Gems and glass were conceptually and physically intermingled in so many historical scenarios that their relation cannot accurately be described as superior-inferior. This paper thus highlights the need to consider glass as more intricate than an “imitation ware,” or second-rate substitute, for gemstones.

The Republic of Venice owned one of the largest, and arguably most valuable, collections of jewels and precious items in early modern Europe. This virtual reconstruction focuses on the sixteenth-century transformation of the Treasury of San Marco into a public showcase for the Republic’s remarkable gem collection, including three large diamonds – gifted to the Republic from Francesco I de’ Medici, an exceptional sapphire – a bequest from Cardinal Domenico Grimani, the crowns of Cyprus and Crete, and numerous objects taken from Constantinople during the Fourth Crusade.  Yet, all of these items were mere supporting players when considered alongside the most valuable item in the collection, the Ducal Corno, the crown of the Venetian Doge. This symbol of power and authority had been in use since at least the 10th century. However, in the early 1530s, Doge Andrea Gritti determined that a new Corno should be displayed in the renovated Treasury. Creating the new Corno was a considerable undertaking, generating significant discussion and debate, the creation of at least three models.  The result: a gem-encrusted statement of sovereignty valued at over 200,000 ducats. Unfortunately, the Corno and many other secular objects housed in the Treasury have disappeared, but previously unpublished documents and digital technology allow us insights into this most precious space.