Ceramic Bowl

(0000.00.7127)

Project Duration: 30 hours

Dimensions: Diameter: 20.5 cm, H. 10 cm

Materials: Wood (Plant material), Metal, Lacquer (Coating), Paint (Coating), Cloth

Object Description: Ceramic bowl, likely wheel thrown. Made of red clay. Conical profile with ring foot. Body flares outward until 2 inches from rim, then becomes vertical. Rim curves in slightly. The surface is mottled with red, beige, and brown. Pitting from firing. Faint root pattern visible on interior. Excavated at Karanis by University of Michigan, 1929 Field Season. No previous treatment record.

Condition:

Object is structurally stable but there is visible salt activity. Chips on foot, side, and rim, the largest being 2.5 cm. In addition to chips, areas of spalling on base. Visible salt efflorescence. Small dark deposits on interior. Evidence of clear coating throughout surface. Coating shows signs of deterioration.

Treatment:

Performed an examination of the surface using an ultraviolet lamp. Orange substance found on most of surface, yet to be determined. Yellow residue in varying locations, suspected to be cellulose nitrate.

Performed test for cellulose nitrate using diphenylamine by taking small chip from surface and a swabbed section of the bowl. Both swab and chip reaction produced a deep blue color, meaning the surface tested positive for cellulose nitrate. Performed test for chlorides using silver nitrate. Brushed sample from interior of bowl reacted with silver nitrate and produced an opaque, white color, resulting in positive result for presence of chloride.

Bowl was desalinated by soaking in a deionized water bath.