German, Sternmarke, Ruhrort, Phosphate Seal, Image & Held by Mike Patrick.
From an e-bay lot, 16mm.
5-pointed star, STERNMARKE curving up around/below // WERK curving down / RUHRORT / 5-pointed smaller star
The seal is of the raised central disc type with an uneven, residual flange around.
From Mike Patrick, "Sternmarke * = STARMARK
Werk Ruhrort = Ruhrort Plant
Ruhrort is a district within the German city of Duisburg situated north of the confluence of the Ruhr and the Rhine. Ruhrort has the largest river harbour in the World, with quays extending nearly 40 kilometres along the river, and it is the principal inland shipping port in Germany. (Wikipedia)
Jan van Oostveen lists a related seal at: Bodemvondstenwereld he suggests 'flour bag (meelzak) seal'".
From Michel Royer, "Not a seal for "flour bag" but phosphate from the 'Thomas' process - See : Euro Plombs, "Sealed leads for agricultural phosphates from the "Thomas" process which is a historic pig iron refining process derived from the Bessemer converter. It bears the name of its inventors who patented it in 1877: Sidney Gilchrist Thomas and his cousin Percy Carlyle Gilchrist. Here the phosphates come from the 'Werk Ruhrot-Meiderich' foundries. The star on the obverse is the registered trademark for "Thomas" phosphates. Seal from the period between the two world wars. ... Ruhrort."
