BW-06023 Invasive appraisement of defective sample (Pear-shape octagon bottle with underglaze-blue illustration of figures)

 

BW-06023 Pear-shape octagon bottle with underglaze-blue illustration of figures is shattered and its pieces were evaluated for ware clay, pigment, craftsmanship, and so forth.

 

Picture on the left is location of shattered pieces before destroying.

First destroying process.

Second destroying process.

Third destroying process.

Piece No. 1 of BW-06023

Piece No. 2 of BW-06023

Piece No. 3 of BW-06023

Joint mark can be seen on the interior belly of the broken ware. 

The clay in Yuan dynasty (1279-1368) mixed porcelain stone with Ma-cang clay in order to increase the quantity of alumina. The mixture will raise the firing temperature and the stability of formation. However, it will decrease plasticity of clay, so large wares will be jointed with sections. 

Magnification of joint mark reveals dry and loose structure with impurities and air holes.

 

The imported pigment’s unique high iron low manganese content transforms into a gorgeous solid color after firing. Dark blue spots and yellowish brown metallic iron rust are found at condensed areas. 

Glittering air bubbles floats on the surface. 

The grayish white clay displays dry and loose structure with obvious air holes and black impurities.