BOOK V. 



109 



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 



Gedigen leberfarbig 

 ertz . . 

 Gedigen geeleriz 



Gedigen graw ertz 



Gedigen Schwartz ertz 



Part Bromyrite 

 (Ag Br) 



Part Cerargurite 

 (Ag CI) (Horn 

 Silver) Part 

 Stephanite 

 (Ag5SbS4^ 



Liver-coloured 



silver 

 Yellow silver 



*Grey silver 



♦Black silver 



*Purple silver 



Argentum rude jecoris 



colore . . 

 Argentum rude luteutn . . 



Argentum rude cineraceum 



Argentum rude nigrum . . 



Argentum rude purpiireum Gedigen braun ertz 



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 greatlj' 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 



Aes rude plumbei 



coloris 

 Chalcitis 



Pyrites aurei 



colore 

 Pyrites aerosus . . 

 Caerideum 

 Chrysocolla 



Molochites 

 Lapis aerarius . . 

 Aes caldariiim 

 rubrum fuscum 

 or 

 Aes sui coloris . . 

 A es nigrum 



In addition 

 artificial products : 



Aerugo . . 



Aes luteum 



Aes caldarium . . 



A eris flos 



Aeris squama . . 



Atr amentum 

 sutorium 

 caeruleum or 

 chalcanthum . . 



Kupferglas ertz 

 Rodt atrament 



Geelkis oder 

 kupferkis 



Berglasur 

 Berggriin und 

 sckifergrnn 

 Molochit 

 Kupfer ertz 



Lebeter kupfer 



Rot kupfer 

 Schwartz kupfer 



Native copper 



Chalcocite (Cu;S) 



A decomposed copper 



or iron sulphide 

 Part chalcopyrite (Cu 



Fe S) part bornite 



(CusFeSj) .. 

 Azurite 



Part chrysocolla 

 Part Malachite 

 Malachite 



When used for an ore, is 

 probably cuprite . . 



Probably CuO from 

 oxidation of other 

 minerals 



Native copper 



♦Copper glance 

 Chalcitis (see notes 

 on p. 573) 



Copper pyrites 



Azure 



Chrysocolla (see 

 note 7, p. 560) 

 Malachite 

 Copper ore 



*Ruby copper ore 



♦Black copper 



to the above the Author uses the following, which were in the main 



Griinspan oder 

 Spanschgriin 

 Gelfarkupfer 

 Lebeterkupfer 

 Kupferbraun 

 Kupferhammerschlag 



Verdigris 



Impure blister copper 



Cupric oxide scales . . 



Blaw kupfer wasser Chalcanthite 



Verdigris 

 Unrefined copper 

 (see note 16, p. 511) 

 J Copper flower 

 [ Copper scale (see 

 note 9, p. 233) 



Native blue vitriol 

 (see note on p. 572) 



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