imported; cobalt-blue; pigments; employed; on; official; blue-and-white; porcelain; Yuan; Dynasty; early; Ming; Dy-; nasty; Mn/Fe; content; ratio; Su; Ma; Li; Qing; (Samarra-blue); Su; Bo; Ni; Qing; (Sumatra-blue); scientific; archae-; ological; research; transliteration;