Thread: Anyone recognize this (thuri? escher?) label?

Well I cannot say if the label is really a very old one. But in general Jimmy, you are absolutely correct.
The thuringian waterwetstones are mined in slate quarries, that consist of in total 442 single layers. From these number 274 layers belong to the so-called clay slate. In this clay slate the whetstone layers were found. In the first phase of mining only the ten best whetstone layers have been mined. Later on, other layes have also been mined, so in the second phase additional 46 layers and in the last phase more than 60 layers have been mined and sold as thuringian waterhones (source: Max Volk: Das Oberdevon am Schwarzburer Sattel----, 1938).
I made a layer table for a presentaton some time ago:



The first phase layers have been the original ones, in the second phase mainly yellowish layers have been mined. The third phase layers had been mined because of lack of material from the previous layers, so they may have been of somehow less quality. Unfortunately there is no specific time frame mentioned somewhere, in which the different layers have been mined.