^360 DESCRIPTION OF PHOSPIIATF.D COPPER. 



The vein of Joscphberg is contained in a mountain, that 

 appears to be composed entirely of argillaceous schist, or 

 .rather a schistose clay containing mica, but in particles 

 scarcely perceptible. 

 Ores accom- The phosphate of copper accompanies copper pyrites, 



panyuig ii. native copper, acicular or earthy oxidule of copper, and 

 blue and green carbonates of copper. The latter is found 

 also in the state of malachite, or compact carbonate of 

 copper. Sulphate of copper too occurs, though very 

 rarely, in this vein, which is very thick, and its extremity 

 comes out to day near the summit of the mountain. 

 pangue. The gangue of these ores is commonly a white or grayish 



hyaliu quartz, frequently tinged of a brown yellow by 

 oxide of iron, which is likewise found uncombined in the 

 specimens. Sometimes the hyalin quartz is tinged of a pale 

 green by the phosphatcd copper. 



Beside the hyalin quartz, but more rarely, a stone is 

 found as its gangue, which the director of the works calls 

 hornstein, but which I am inclined to consider as a true 

 agate quartz. If it be rare to see this agate quartz form 

 the mass of the specimens, it is frequently found lining 

 their cavities. The surface of the phosphate of copper, 

 particularly of the drusy, is often covered with a pellicle 

 of common chalcedony, which is so thin, as not to be 

 always perceptible; but if a fragment be exposed to the 

 blowpipe, the chalcedony immediately separates from the 

 phosphated copper, and appears with its white colour. 

 This pellicle sometimes gives the druses the appearance of 

 mpuldiness, or renders their surface velvetty. In the ca- 

 vities too, that contain the phosphated copper, a white 

 chalcedony, pr sometimes slightly tinged with blue, is 

 found in separate and parallel cylindrical tubes, and occa- 

 sionally in slender threads, crossing each other in various 

 directions. These are either white or rose-coloured. In 

 the axis of the tubular chalcedony we frequently find an 

 opake line, apparently owing to the oxide of iron. Some- 

 times among the fibrous phosphate of copper particles of 

 green carbonate of copper are found, which are distinguish- 

 able by their paler colour. 



The 



