Pretty internal glaze of blue or light gray color.
Signed TURNER below.
Work dating from 1949, two years before he became professor of art ceramics at Black Mountain College. Robert Turner was a recognized artist and professor emeritus in art ceramics.
I let you read his biography on his website: https://www.robertcturner.com/bio_complete.html
or on a famous online encyclopedia: https://en.wikipedia.org/wiki/Robert_Chapman_Turner