Black/white vintage ceramic vase from the 1950s

Ceramic vase from the fifties. Beautiful vintage model made of black/white ceramic. Marked on the bottom 1/12 N 20 and a signaling that is unknown to us. The condition is good, but it seems that there has been a small restoration of a dot at the bottom edge, see details. The dimensions are 19.5 cm high and 8 cm in diameter.