the earth or stone too far outweighs the gold. A vein which contains a larger proportion of silver than of gold is rarely found to be a rich one. Earth, whether it be dry or wet, rarely abounds in gold; but in dry earth there is more often found a greater quantity of gold, especially if it has the
| Argentum rude jecoris colore | Gedigen leberfarbig ertz | Part Bromyrite (AgBr) | Liver-coloured silver |
| Argentum rude luteum | Gedigen geelertz | Yellow silver | |
| Argentum rude cineraceum | Gedigen graw erlz | Part Cerargurite (AgCl) (Horn Silver) Part Stephanite (Ag5SbS4) | *Grey silver |
| Argentum rude nigrum | Gedigen schwartz ertz | *Black silver | |
| Argentum rude purpureum | Gedigen braun ertz | *Purple silver |
The last six may be in part also alteration products from all silver minerals.
The reasons for indefiniteness in determination usually lie in the failure of ancient authors to give sufficient or characteristic descriptions. In many cases Agricola is sufficiently definite as to assure certainty, as the following description of what we consider to be silver glance, from De Natura Fossilium (p. 360), will indicate: "Lead-coloured rudis silver is called by the Germans from the word glass (glasertz), not from lead. Indeed, it has the colour of the latter or of galena (plumbago], but not of glass, nor is it transparent like glass, which one might indeed expect had the name been correctly derived. This mineral is occasionally so like galena in colour, although it is darker, that one who is not experienced in minerals is unable to distinguish between the two at sight, but in substance they differ greatly from one another. Nature has made this kind of silver out of a little earth and much silver. Whereas galena consists of stone and lead containing some silver. But the distinction between them can be easily determined, for galena may be ground to powder in a mortar with a pestle, but this treatment flattens out this kind of rudis silver. Also galena, when struck by a mallet or bitten or hacked with a knife, splits and breaks to pieces; whereas this silver is malleable under the hammer, may be dented by the teeth, and cut with a knife."
Copper Minerals.
| Aes purum fossile | Gedigen kupfer | Native copper | Native copper | |
| Aes rude plumbei coloris | Kupferglas ertz | Chalcocite (Cu2S) | *Copper glance | |
| Chalcitis | Rodt atrament | A decomposed copper or iron sulphide | Chalcitis (see notes on p. 573) | |
| Pyrites aurei colore | Geelkis oder kupferkis | Part chalcopyrite (CuFeS) part bornite (Cu3FeS3 | Copper pyrites | |
| Pyrites aerosus | ||||
| Caeruleum | Berglasur | Azurite | Azure | |
| Chrysocolla | Berggrun und schifergrun | Part chrysocolla | Chrysocolla (see note 7, p. 560) | |
| Part Malachite | ||||
| Molochites | Molochit | Malachite | Malachite | |
| Lapis aerarius | Kupfer ertz | Copper ore | ||
| Aes caldarium rubrum fuscum or Aes sui coloris |
Lebeter kupfer | When used for an ore, is probably cuprite | *Ruby copper ore | |
| Rotkupfer | ||||
| Aes nigrum | Schwartz kupfer | Probably CuO from oxidation of other minerals | *Black copper |
In addition to the above the Author uses the following, which were in the main artificial products:
| Aerugo | Grunspan oder Spanschgrun | Verdigris | Verdigris | |
| Aes luteum | Gelfarkupfe | Impure blister copper | Unrefined copper (see note 16, p. 511) | |
| Aes caldarium | Lebeterkupfer | |||
| Aeris flos | Kupferbraun | Cupric oxide scales | Copper flower | |
| Aeris squama | Kupferhammerschlag | Copper scale (see note 9, p. 233) | ||
| Atramentum sutorium caeruleum or chalcanthum | Blaw kupfer wasser | Chalcanthite | Native blue vitriol (see note on p. 572) |
