German, Sternmarke, Ruhrort, Phosphate Seal

German, Sternmarke, Ruhrort, Phosphate Seals, Image & Found by Peter van Lierop.
Found in Gemert & Son, Netherlands, 16mm, c 4g.

Five-pointed star, STERNMARKE curving up around/below // WERK / RUHRORT curved up

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."

See also BSG.BS.01628.