NATIVE AKSENIATE OF LEAD. 3gJ 



was found. The veins of it are, in general, from six to 

 ten inches wide, and they diverge on going west. Some 

 particles of this lead ore have been found in the southern 

 part, after the separation of the lodes ; but the northern 

 lode does not contain any, until the junction takes place. 

 This ore is intermixed with some native copper, very rich 

 gray copper, and black copper ore, and some is mixed with 

 quartz. The walls of both veins are killas. 



§ ^. This mineral is regularly crystallized. The form of I^escriptionof 

 its most perfect crystals is a hexaedral prisnj; they are of ^'^'^ ™'"^''*^- 

 different sizes, from one tenth of an inch in diameter, to 

 the size of a hair. The longest which I have seen do not Form of Us 

 exceed three tenths of an inch in length: these terminate ^'^^^*^'* 

 in a plane, at right angles, with the axis of the prism; but 

 the crystals of a smaller size are frequently drawn out into 

 a very taper acumination, which appears to be a six-sided 

 pyramid. A number of smaller crystals are often closely 

 packed together in bundles, which are bent in dirtercnt di- 

 rections, and terminate in a point. The larger crystals 

 either stand alone, or adhere, on their lateral planes, to 

 the gangue, or are confusedly matted together in a mass. 



Some of them are hollow, as if an internal nucleus had 

 been destroyed ; arid sometimes this internal nucleus over- 

 tops the external laminae. The gangue is a white quartz, 

 ■which frequently exhibits on its surface the appearance of a 

 partial decomposition. 



The red octaedral copper ore, and the copper into which 

 that ore passes, are often intermingled with the crystals of 

 this lead ore and inbedded in them. 



The colour of these crystals consists of a variety of tints Colour, 

 of yellow. Some are of a beautiful wine yellow resem- 

 bling the Brazilian topaz : this, in the greater number of 

 specimens, passes into a delicate Isabella-colour: while, in 

 other cases, we have the honey-yellow mingled with brown 

 hues of diflferent intensities: so that we meet with crystals 

 resembling dark brown sugar-candy, or common resin. 



Some of the crystals are beautifully transparent, while Transparency, 

 others possess this quality in part only, at their extremities, 

 or in inferior degrees throughout their whole lengths. 



The 



