This bowl is made from a high fired grey stoneware, with a green/grey ash glaze. The inside is decorated with a striking pattern of concentric lines.
The piece is 13 cm in diameter, and 5 cm high. This glaze is considered an early glaze, one of the first ever made.
The Mak.frankfurt has a tl-tested similar piece, dated 700-500 bC, shown in the book Feuergeburten (pic. 19) The region is Qingqiang, Jiangsu province.
Another example is shown in the famous book by He Li, cat nr 40.
Online you can find one in the Metropolitan Museum, Accession Number: 1977.449.5
Suzanna Valenstein names and pictures an example in A Handbook of Chinese Ceramics, dated 7th- 5th century bC.
This leads to the conclusion that this type of bowl is to be placed in Spring and Autumn period.
The eastern Zhou is divided in Spring and Autumn period (722-481 bC) and Warring States (481-221 bC) It was a troubled period in China, but nonetheless marked by technological and cultural milestones. To name two, the discovery of iron tools and the rise of Confucianism and Taoism.