Conservation

Ceramic Pitcher recovered from the Monitor. Photo Credit: Courtesy of The Mariners’ Museum

Siliceous Artifacts

Siliceous artifacts found on the Monitor include those that are made of glass, ceramic, and stone. They are all derived from minerals in the earth's crust which are in the same chemical form, or a similar heated form, that they have been in for thousands of years. Therefore, they are relatively chemically stable and most degradation under water occurs as a result of physical decay such as erosion by sea water and particles like sand grains. Depending on the pore sizes of the artifact, salts can be damaging as they dry out into crystalline form and exert pressure on pore walls. In addition, stains from soil and encrusting marine organisms may also damage the artifact.

Wine bottle recovered from the Monitor. Photo Credit: Courtesy of The Mariners’ Museum

Glass artifact deterioration is a function of its composition, its firing history, and the wreck environment and duration. They can be extremely brittle when removed from the water so they are often packed carefully in marine sediments before they are lifted. Once out of the ocean, it is important to keep them damp and remove any soil or encrusting organisms to initially stabilize them. Ceramic artifacts are made from fired clay. They are typically placed in a mixture of sea water and fresh water that is replaced daily with a gradual reduction in the amount of sea water. Stone artifacts are cut from rocks and are usually hard and relatively inert. They must be kept wet when excavated so that the salts can be removed from their pores by slowly diluting the sea water concentration and mechanically removing any encrusting organisms that have attached themselves to the artifact's surface.