Description of the Most Principal Mineral Ores

practical? original: "practica"
and g?
to be.

and is the true masterpiece, and without such grounded art of calculation, the assaying of such places is not to be esteemed. Therefore, every assayer should apply himself most diligently to this, as well as to other things useful for assaying and whatever pertains to the same, and learn everything well, so that he may perform his tasks perfectly.

Excuse of the author for omitting to mention some things.

And although it would not have been unhelpful to make such things a little more detailed here in the introduction, and also [to speak] of the origin of metallic ores, and how they are supposed to have grown or still be generated today in the mountains, in the veins or lodes, of which the ancient naturalists and philosophers have various opiniones opinions and thoughts. Likewise, of particular courteous strikes and dips of the veins, and similarly of shifts and other accidents that are supposed to create ores, according to which the miners guide themselves, prospect, and have their rules. But since this would become too long, and the opinions of those philosophers and the rules of the miners do not agree in all things, but often fall far short, and since the philosophers have already written great books about it, from which the common miners can improve themselves but little, I have omitted it here for the sake of brevity.

A woodcut depicts an elaborate typographical ornament featuring symmetrical intertwined scrollwork, leafy flourishes, and heart-like shapes, typical of sixteenth-century book design.