Cobalt 钴, 碗花 (also 石花)

Cobalt is a metal, but rarely used as such. Its main use is in the form of cobalt oxide, usually powdered, as a pigment. Fired underglaze at 1300° C, it turns deep blue and was used for the famous white-and-blue wares produced in Jingdezhen and other porcelain kilns since the 14th century.

Cobalt oxide was highly valued and eventually consumed i considerable quantities as a pigment, yet its origins are uncertain. Art history has established an influence from the Islamic world during the later Song and Yuan periods. In the Near and Middle East, blue, preferably turquoise, but also cobalt blue, had been a culturally highly esteemed colour since antiquity. With the expansion of overseas trade, white-and-blue ware may even have initially been developed as an export good for the Islamic markets (Zhao Bin 2013).

The pigment is assumed to have initially been important from the Middle East. This is strongly suggested by early Chinese designations as Sumali-green 苏麻离青 and Suboni-green 苏勃泥青.

However, it appears that kilns in Yuxi 玉溪, Jianshui 建水, and Lufeng 禄丰 in southern central and central western Yunnan 云南 already produced white-and-blue wares in the Yuan period (Shang Gang 1999, 192). This suggests the presence of cobalt exploitation in the region by this time.

The widespread exploitation of the mineral in the Southwest is documented from the late Qing to the mid-20th century. Shen Kaxiang 沈卡祥's initial on written records and sites research suggests that cobal mines were commonly small-scale exploitations that washed cobalt oxide from mineralized soils (unpublished research by Shen Kaxiang).

Sites of historic cobalt mining are occasionally known from place names. Thus, a relatively large number of villages by the name of Wanhuachang 碗花厂 or Wanchang 碗厂 exist, especially in northeastern Yunnan and northwestern Guizhou 贵州, but also in other parts of Yunnan.

As silver and cobalt deposits can occur together, the exploitation of silver may lead to cobalt, either as co-exploitation or cobalt becoming an alternative when richer silver veins were exhausted.

For reasons of work economy, this project cannot pursue cobalt mining systematically. We cover cobalt mines in areas where systematic fieldwork is planned, such as northeastern Yunnan.