I recently found several of the photographed items in the Vosges Mountains of eastern France. 1 1/4" x 1 1/4". About 1/8" thick. Hard rubber core. Looks like greenish plastic or alabaster edges. Edges are rounded but rough cut. Doesn't look machine cut. Found in Vosges Mountains and nearby valley (Amercian/German combat Oct-Dec 1944). Any identification help would be appreciated. Thank you.