Origin of the Red Color of Satsuma Copper‐Ruby Glass as Determined by EXAFS and Optical Absorption Spectroscopy

Abstract

The origin of the ruby color of Satsuma glass, a famous copper-ruby glass produced in Japan in the mid-19th century, has been examined by electron microprobe analysis (EPMA), X-ray absorption fine structure (XAFS), and optical absorption spectroscopy analyses. CuK XAFS analysis reveals that the major component of copper in the ruby glass consists of Cu(I) ions in the glass structure. This species is distinct from Cu 2 O (cuprite), which we conclude is not responsible for the ruby color. Optical absorption spectra measured at 300 and 77 K clearly distinguishes the absorptions due to the colloidal particles of metallic copper and Cu 2 O. It is concluded that the trace amount of copper in the ruby glass, which is below the detection limit of the EPMA and XAFS techniques, exists as metallic copper particles of nanometer size and is responsible for the ruby-red appearance of the Satsuma glass.

The Use of Metal Nanoparticles to Produce Yellow, Red and Iridescent Colour, from Bronze Age to Present Times in Lustre Pottery and Glass: Solid State Chemistry, Spectroscopy and Nanostructure

“…Reducing the dimension of matter domains down to the nanometre scale confines the electronic and vibrational wave functions, which results in unique properties and opens a wide range of potential applications in different domains such as: i) optics and microwaves : pigments for the cosmetic industry, fluorescent markers and quantum dots, photonic crystals (multiplexing and switching in optical networks), quantum , 9 th century), c -e) Fatimid shards depicting a lion or a leopard (c) and a palmette (d, e) both excavated from Fustat (12 th century, Cairo, Egypt); for the later shard two orientations are shown; f) red HispanoMoresque and g) Mudejar (16 th century, Andalusia) potteries (Sèvres Museum Collection); the later depicts the Latin HIS inscription, Iesus Humanitas Salvator, and after 180 d turn, an Arabic one, almulk, the Kingdom; h) and i) are modern red and gold shine lustres from Eva Hundum. (Photograph, Ph.…”

Colored semi-transparent Cu-Si oxide thin films prepared by magnetron sputtering

“…The incorporation of copper in silicate glasses is a well known procedure to color them. For example, the characteristic ruby color is achieved by incorporation of metallic Cu colloidal particles in transparent silica or sodium silicate matrix [9,10]. It is also well known that glasses with reddish color can be obtained by the incorporation of Cu 2+ ions and CuO clusters in these transparent matrices [3,4,9,12].…”

“…The range of variation of the optical characteristics of the films achieved in this way can be very wide if the two oxides mixed together have rather different refractive index and extinction coefficient. This idea is related to the common use of transition metal oxides to color glasses, traditionally employed in stained-glass windows and other hand-craft glasses [3,4,[9][10][11][12].…”

Estudio de los factores que gobiernan la coloración de los esmaltes cerámicos

“…Lo ideal es que la forma de los espectros este determinada por las características de los pigmentos y el esmalte influya en la intensidad, pero esto no siempre sucede debido a las transformaciones de fases y a la difusión de las bases, fenómenos que son inevitables a altas temperaturas. Más estudios en este sentido fueron desarrollados por Nakai y col (7). También se pueden citar los trabajos de Thiele y col. (8,9) donde se tienen en cuenta efectos debidos a la dispersión de la luz.…”