The symbol of Wusheng Laomu (無生老母), Wujimu (無極母), the primordial fire or matrix of all things worshipped in the Yiguandao (一贯道) and other Xiantiandao Chinese religions. It is used as a symbol of Yiguandao, specifically. It is a stylised version of the Chinese character 母 mu, "mother".
Own work
Aethelwolf Emsworth.