The name used for the Tenmoku bowls (aka Temmoku bowls) is in fact Japanese. The Chinese have no special name for this type of tea bowl. Originating in Song dynasty China, Tenmoku bowls were made at the Jian kilns (aka Jianyang kilns).
During the Song dynasty Buddhism flourished in Japan and many
Japanese monks travelled to Tianmushan (Tianmu mountain) in China, which
at the time was a center for Zen Buddhism. 'Tianmu' is read 'Tenmoku'
or 'Temmoku' in Japanese.
When they returned, the monks brought brought the custom of tea drinking with them, which in China served to keep the monks awake during religious practices. They also brought with them the bowls used for drinking tea. That is the origin of its Japanese name.
The bowls are basically a type of black glazed pottery with streaks
of dark brown clay. The black glaze is first applied, then the brown
glaze is added from the top rim.
Manufacturing place: Jian kiln (aka Jianyang kiln) in todays Fujian province, on the east coast of China.
See Jian wares.
Jianyang tea bowls are never completely black. Completely black tea bowls of this type were manufactered at Jizhou kiln, not far away from Jianyang.