Description of the Most Principal Mineral Ores

bordering countries, such as Silesia, Moravia, Meissen, and Saxony, there are for the most part silver mines, and what miners, wardens, assayers, and smelters are found in those places generally endeavor only to assay silver ore and make assays thereof, as well as of other metals that also have silver with them, of which, however, many are not entirely experienced in the trade or have thorough reports. To serve them, I have taken this upon myself, wherefore I have also treated it somewhat more extensively than the other metals and their probations. This I did not wish to leave unmentioned at the beginning.

Of the silver ores, and how the same are to be recognized differently.

Silver ores are of many kinds.

A decorative drop cap initial 'D' features elaborate floral scrollwork and foliate motifs within a square border. The silver ores are found of many kinds and colors, and when they are not quite solid and good, they are not easily judged by their appearance as to what approximate content of silver they hold. Therefore, the assaying by the ancients was directed toward this with diligence, and thus was invented, and also in the many years since, it has been sought after and improved so much that one can now find the certain content of every ore and thereon base the smelting work and the calculation (whether one can survive the costs according to the content). However, it is to be known besides that as many kinds of silver ores as there are, so many kinds of their nature are there, and the assaying of silver ores should properly be directed according to the nature of each ore in the smelting as well, because one cannot assay hard-fusible, stubborn, coarse, and raw ores the same as soft-fusible, mild, and subtle ores. For according to whether an ore assay is stubborn or infusible, it must be helped in the assaying, as one can recognize from much practice before the assaying. How they behave in the fire, thus it also happens in the same way in the large fire with the smelting, and if one does not know the nature of the ore before the smelting, and how it will behave in the fire...

Difference to be kept in assaying between fusible and infusible ores.