STUDY ON THE PIGMENTS IN THE CRUCIFORM GALLERY OF ANGKOR WAT, CAMBODIA*

Summary of the pigments Based on the analyses by the electron probe X-ray microanalyser and the X-ray microdiffracto-meter for several samples of pigments collected from each area, the substances constituting thepigments in the cruciform gallery of Angkor Wat are summarized in Table 1.Red, orange, white and black pigments were mainly used in the cruciform gallery. The redpigment consists mainly of hematite and quartz, and contains abundant impurities such as SiO 2 (10–40 wt%) and Al 2 O 3 (10–20 wt%). Because laterite consists mainly of hematite, goethite,quartz and kaolinite, and the major components are Fe 2 O 3 , SiO 2 ,Al 2 O 3 and H 2 O (Uchida et al .1999a), it is supposed that laterite was used as a raw material for the red pigment. Abundant ironhydroxide (goethite) with a yellowish brown colour is contained in laterite. Therefore, it ispossible that laterite was burned to obtain a vivid red colour. The orange pigment consists mainlyof minium and contains Pb–Cl compounds, calcium phosphates, calcium oxalate hydrates,calcite, anglesite and gypsum. The white pigment is composed of Pb–Cl compounds, white lead,calcium oxalate hydrates, calcium phosphates, calcite, anglesite and gypsum. Three kinds ofblack pigments were found: lead dioxide derived from minium by oxidation, carbon black andgypsum discoloured into a black colour due to the absorption of soot and dust. Calcium phos-phates are frequently found in the pigments. Some calcium phosphates may be derived from batguano (Fusey 1991; Uchida