Rocks, Minerals, and the History of Art

Catalog description

This online course investigates select rocks and minerals used in the production of art between the Prehistoric Era and the Early Modern period. Topics covered include chemical and physical properties, occurrence in nature, the processes by which natural materials are acquired and worked, their symbolic and monetary value, and specific works of art in which they are found. Each material (ochre, garnet, lapis lazuli, rock crystal [quartz], igneous rocks [basalt, diorite and porphyry], alabaster and marble) is addressed in a 2-week unit. The seven units are split equally between scientific analysis of the materials and art historical case studies. A final project integrates Geosciences and Art History topics to investigate the use of a chosen natural material in a specific work of art. Each material addressed in the course plays a crucial role in the history of art, and each one was particularly prized for its physical and material properties (color, hardness, etc.). Ochre was the first known pigment, and was in use by early humans for bodily adornment and for drawing and painting in caves and shelters as early as 100,000 years ago for bodily adornment and 40,0000 years ago in cave art. Its availability worldwide and in multiple strong colors made it a desirable choice. Lapis lazuli, by contrast, was difficult to obtain, and difficult to refine as a pigment. It was first used to make small sculptures and cylinder seals in the Ancient world, and was prized for its brilliant blue color. The difficulty in grinding and purifying blue pigment from lapis lazuli made it one of the most expensive pigments in the Medieval and Renaissance world--it was worth its weight in silver! Pure blue lapis pigment, when found in a painting, is always a sign of great expense and importance. Rock crystal was valued for its clarity and purity, and its extreme brittleness meant that works made from it were valued for their intricacy and fragility. Nero reportedly destroyed two elaborate crystal goblets in a rage, and in so doing, deprived future generations of masterpieces of the sculptor's art. In the Ancient Near East and Ancient Egypt, rock crystal was frequently used for amulets and other magical objects, while in the Medieval world, its purity was seen as a metaphor for the Virgin Mary. Garnet had a similar symbolic value in the Middle Ages: its red color was related to the blood of Christ, and it was thus used frequently in liturgical vessels. In the Ancient world, the rich red tone of garnets was prized in jewelry and in small-scale relief carvings. Igneous stones like porphyry, basalt and diorite were particularly prized for their extreme hardness and permanence, and thus the Law Code of Hammurabi was iinscribed on basalt to ensure its permanence. Other Ancient Near Eastern rulers had images of themselves made from basalt and diorite in order to ensure that those works would survive for centuries. Imperial porphyry, an igneous stone with a rich red-purple color, came from a single remote quarry in the Egyptian mountains. Its use was reserved just for the Imperial family in Rome, and it was used for carved sarcophagi, for columns, for colored veneers on floors and walls, etc., as a sign of Imperial authority. Marble is of course one of the most familiar of all art materials, used frequently for sculpture from the very beginnings of art production. The Greeks and Romans in particular took great pains to obtain different types of marbles with specific colors, veining patterns, etc., for use in both sculpture and architecture. Finally, alabaster is one of the easiest of all stones to work: it is so soft that one can make a mark simply with a fingernail! Its intricate banding and translucency made it a favorite material for thin-walled bowls and vases in the Ancient Near East, Ancient Egypt, and in the Classical world. Later, in Early Christian and Medieval Italy, it was used for windows instead of glass--sun shining through alabaster casts a golden glow into a church interior. By the Late Gothic period, alabaster was being exploited as an easily sculpted material throughout Europe, with major quarries and workshops in England (Nottingham), France, and Northern Spain.