68 THE PROSPECTOR'S HANDBOOK. 



Streak colourless. 

 H._ 3 to 3-5 ; S.G. 6'5. 



Composition 75 per cent, of lead, the rest carbonic 

 acid, &c. 



Before B.F. a lead bead is obtained. 



If dissolved in nitric acid, and a piece of clean zinc be 

 dipped in the solution, brilliant lead laminae will be precipi- 

 tated on the zinc. Effervesces in acids. Red oxide is some- 

 times found on surface of lead ores, notably at Leadville, 

 Colorado, on the carbonates. Specimens of a carbonate 

 should always be examined for fragments of chloride of 

 silver or chlorobromide of silver. 



Pyromorphite. 



Colour greenish, sometimes bright grass green, the 

 hexagonal crystals having a greasy lustre, also 

 yellowish, brownish, and sometimes dull violet. 



Streak whitish or yellowish. 



Lustre more or less resinous ; generally translucent. 



H. 3-5 to 4 ; S.G. 6'5 to 7. 



Contains 78 per cent, of lead, as well as phosphorus, &c. 

 Heated on charcoal before the B.F., a globule is formed 

 which crystallizes on cooling, while a yellow oxide of lead 

 incrustation is seen on the charcoal. 



With carbonate of soda in R.F. yields a lead bead. Is 

 soluble in nitric acid. 



Chromate of Lead. 



Is a yellowish mineral containing protoxide of lead and 

 chromic acid. It blackens before the blowpipe and leaves 

 shining globules of lead in the slag. Produces a yellow 

 solution in nitric acid. 



Sulphate of Lead. 



A white, grey, greenish, or bluish, translucent or opaque 

 mineral, with an adamantine lustre. Contains protoxide of 

 lead and sulphuric acid. Rather like carbonate of lead, but 

 is softer and does not effervesce in an acid. 



Galena (generally mixed with other metals) is the usual 



