The “aubergine” enamel (eggplant), also known as Qiepi zi, was made from a manganese containing byproduct from the purification process of the Chinese local cobalt, which was processed into a pure sapphire blue. Different shades of Aubergine from intense ‘brinjal’ purple to brown and light watery purple were all made by the Chinese low-grade cobalt-iron-manganese or mixed with lead and quartz sand.
In Chinese culture, the number six holds symbolic significance and is associated with balance, harmony, and unity.