An Archaeometric and Morphological Study on a Rare Intact Pair of High Tang Dynasty Monochrome Blue-Glazed Beaded Covered Jars (Specimens SG-TSC-04 & SG-TSC-05)

Abstract This monograph provides an exhaustive archaeometric, morphological, and iconographic investigation into an exceptionally rare, intact pair of monochrome cobalt-blue glazed covered jars with relief-molded beaded decorations (Lianzhuwen, 連珠紋), dated to the High Tang period (late 7th to first half of the 8th century CE). While Tang Sancai lead-glazed wares occasionally incorporate minor cobalt highlights via spattering or localized brushwork, the execution of full monochrome cobalt-blue coverage (Chun Lanyou, 純藍釉) over entire vessels represents the utmost pinnacle of imperial luxury, directly associated with court monopoly and diplomatic tributary networks spanning Central Asia and Persia. Through precision metrology, the specimens demonstrate a strictly coordinated pair relationship (a Zimoguan / Mother-Child jar set) engineered with intentional foot-ring modifications (5.3 cm vs. 5.4 cm) to optimize structural centers of gravity. Microscopic optical examination (100×) confirms authentic post-burial phase transformations, including dense fly-wing reticular crazing (Yingchiwen, 蠅翅紋), sub-surface secondary lead carbonate recrystallization (white devitrification veining), mother-of-pearl iridescence (Yinhua, 銀化), and authigenic calcite/quartz encrustations within the hermetically sealed internal chambers. Iconographically, the relief beaded borders and five-knobbed rosette bosses physically transcribe Sasanian Persian repoussé silverware into northern Chinese high-density kaolinitic white earthenware (Gongxian kiln type). Keywords: Tang Sancai, Monochrome Cobalt Blue, Sasanian Metalwork, Beaded Border (連珠紋), Gongxian Kiln, Iridescence (銀化), Reticular Crazing (蠅翅紋), Archaeometry.