Antique Islamic Medieval 11th–13th c Khwarezmian Empire Sgraffito Ceramic Bowl

This is an antique earthenware terracotta bowl from the Islamic Medieval era 11th - 13th century AD (391 AH – 700 AH) that originated from the Khwarezmian Empire of Central Asia, specifically from Bamiyan. The bowl has a flaring body that rises from a short foot. The surface of the walls is cream-colored with an incised zigzag motif that is divided by vertical green lines radiating from the center. The interior has a central medallion with a stylized motif of bird heads that is also incised (known as "Sgraffiato").
 
Sgraffiato - a term used to describe a widespread type of glazed pottery whereby the surface was covered with a fine pale slip which was incised through to the underlying body and then covered with a transparent glaze, and often highlighted with splashes of colored glaze.
 
CONDITION: In good, intact condition with signs of age with old iridescent earthen patina and wear.
DIAMETER: 18 cm (7.09 inches) Height: 8 cm (3.15 inches).
REFERENCES:
"Ceramics from Islamic Lands. (In association with The al-Sabah Collection Dar al-Athar al-Islamiyyah, Kuwait National Museum)" by Oliver Watson.