Fritz Heckert Enameled Glass Vase, Ludwig Sütterlin form, ca. 1900

According to the book Josephine Glassworks, Jugendstil - Art Deco - Modern, by Dr. Stefania Zelasko, this form was designed by the graphic artist Ludwig Sütterlin (b. 1865, d.1917) for the Josephine Glassworks, ca. 1900. The enamel decoration stylistically to me looks like the work of either Dr. Willy Meitzen or Adolf Heyden, but could even be that of Sütterlin himself. The light blue glass ground has an opalescent quality, and is reminiscent of the color that Loetz called "Ozon". The glass glows bright green under black light (see photo 3). It is unmarked.