In any event, this piece is a vase and was probably made during the late 1930s or perhaps 1940s, and no, it is not an antique — yet. It is a good size, and has nice “Art Moderne” decoration.

The vase painter then applied black slip to the areas to be decorated and used a sharp tool to incise any necessary details, a process that revealed the color of the clay beneath. After the decoration ...

Appraisal: 1927 Rookwood Shirayamadani "Black Opal" Vase, in St. Louis Hour 2.