Micro-Raman spectroscopy was applied to the mineralogical characterization of Bronze Age Cypriot ceramic fragments from the Lapatsa Tomb collection of the Ringling Museum of Art. Micro-probing was carried out on the surface and the results were compared with those of micro-probing from the crosssection of the two samples studied. Significant statistics were collected from 500 locations on each sample. Various phases were identified: quartz, albite, calcite, ilmenite, anatase, rutile, hematite and maghemite. It was determined that the different red coloration of both pieces is due not only to different hematite concentrations, but also to different grain sizes. The presence of low-temperature albite and anatase suggests low firing temperatures. The presence of hematite suggests firing in an oxidizing atmosphere.

Micro-Raman spectroscopy and the laser-induced transformation technique were used for systematic study of five coloured glazes on Saint John the Baptist (29 inch tondo), a majolica terracotta relief attributed to Luca Della Robbia and on permanent exhibit in The John and Mable Ringling Museum of Art. We suggest that S 3 − ions in a lead silicate matrix, called 'lead ultramarine', could contribute to the famous Della Robbia blue colour, in addition to the effect of Co atoms as suggested previously by Pappalardo et al. (2004). The original yellow glaze contains lead(II) antimonate. The green is a mixture of the yellow and blue pigments, the brown contains hematite, and the white glaze contains tin dioxide as an opacifier. The use of lead oxide as a main fluxing agent is confirmed by laser-induced micro-crystallization. KEYWORDS : MICRO-RAMAN SPECTROSCOPY, MAJOLICA GLAZES, ULTRAMARINE, PIGMENTS, RENAISSANCE, DELLA ROBBIA Figure 5 Representative Raman spectra of (I) the white glaze (the inset shows the extended spectral range of the same spectrum) and (II) cassiterite powder (Aldrich).

Micro-Raman temperature study and X-ray fluorescence (XRF) spectroscopy were used for characterization of the blue glaze on Saint Johnthe Baptist -majolica terracotta relief attributed to Andrea Della Robbia and Saint Johnthe Baptist withCross -majolica terracotta statue attributed to Giovanni Della Robbia. Both objects are on permanent exhibition in the John and Mable Ringling Museum of Art in Sarasota, FL. This study proves that the detection of the 548 cm −1 Raman band alone cannot serve as evidence for presence of lazurite crystallites in the pigment in the glaze. It was established that the famous Della Robbia blue is due to the combined effect of Co-Ni-Cu-Zn atoms and S 3 − ions embedded in a lead silicate matrix. It is proposed that the Della Robbia family used Co-containing sulfide ores as a source for manufacturing their blue pigments.