Microstructure from Xuande Reign

    There two porcelain shard samples from Xuande Reign were investigated. One is from big plate. This shard is with length 44cm, width 8.5cm, and thickness 1cm.

    The other one is from jar, painted with dragon clow and with the mark of ‘made in Xuande Reign’. The shard is with length 20cm, width 13cm, and thickness 1,2cm.

    With naked eyes, the iron spot from these two samples showed very obvious. The iron spot on the shard big plate 003 appeared red-brown color. While the iron spots on the shard jar 022 appeared some silver metal luster.

1 microstructure of iron spots

Photos of iron spots from big plate 003.

Photos of iron spots from jar 022.

    Although the iron spots from two shard samples are quite different with naked eyes, there are similarities under the microscope. Basically, there are two kinds of crystal, as on the sample from Hongwu shard 021. On the Hongwu sample, the grey crystal (marked as black arrow on the photos)and the red-brown crystal (marked as orange arrow on the photos) appear on the same iron spot. On the Xuande samples, these two crystals also appeared on the same iron spots.  Except for this, the grey crystal also appeared solo, which indicated that possibly, two different types of cobalt pigment were used during Hongwu and Xuande reign respectively. On photos, marking ‘G’ presents glossy glaze.

2 glaze on the surface

    On the surface the glaze of Shard Xuande BW big plate 003 showed crater structure. The craters are not as densely as those from the sample of Hongwu reign.