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Constitution of Copper‐Red Glazes
Author(s) -
BROWN S. F.,
NORTON F. H.
Publication year - 1959
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1959.tb13566.x
Subject(s) - glaze , copper , dissolution , materials science , colloid , metallurgy , metal , mineralogy , reducing atmosphere , chemistry , ceramic
The red colorant in reduced copper glazes has been positively identified as metallic copper in colloidal form. The identification was made by forming a copper red in sodium metasilicate and dissolving the resultant glass in water, thus concentrating the coloring material until good X‐ray diffraction patterns of metallic copper were obtained. It was found that excellent reds could be obtained by the usual alternating cycle of reduction and oxidation, by the addition of reducing agents to the glaze, or by a uniform, slightly reducing atmosphere. Copper nuclei were formed between 800° and 1250°C. These nuclei could be grown to colloidal size at about 650°C. Too great a growth gave muddy reds and then blacks.