In a mining context, the term ‘assaying’ refers to the testing of materials. Assaying, as practised in smelting foundries, is considered the oldest form of chemical analysis.

Before smelting, the metal content of a small sample of the coarse copper delivered was tested. The technical processing was carried out on a small scale.

The coarse copper had already been tested for its copper and silver content by the mining authorities. The test was repeated in Grünthal to verify that the payment was correct. The average silver content of coarse copper mined in Saxony during this period was around 0.53%.

At the same time, they worked out how much raw material was required for the smelting process.

The Assay Office was originally in an annex to the Saigerhütte. It housed the assay furnace, scales and other equipment.