256 PHYSIOGRAPHY. 



Vauquelinite. 



VAUQUELINITE. Lead-Baryte. 



Primary form. Oblique rhombic prism. 



Minute crystals, nearly resembling the annexed figure, 



Fig. 460. 



if the obtuse edges o a be replaced, and the figure be com- 

 pressed parallel with P, and joined in regular compositions, 

 parallel to a plane, which passes through the crystals in the 

 direction of e e, and intersects the acute lateral edges. In- 

 clination of P on P 7 from the other individual, nearly 134 

 30'; of the edge o a, or its replacement on P, about 149. 



Fracture uneven. Surface, P smooth and even, the rest 

 of the faces a little curved. 



Lustre adamantine, often faint. Color blackish green, 

 olive-green. Streak siskin-green, often inclining to brown. 

 Faintly translucent, with a fine olive-green tint, opake. 



Rather brittle. Hardness =2-5 . . . 3-0. Sp. gr. = 5'5 

 ...5-78. 



Compound Varieties. Botryoidal, reniform, massive : 

 composition generally impalpable, surface drusy or roqgh, 

 fracture imperfect and flat conchoidal, lustre faintly resinous. 



1. Alone, before the blow-pipe, it intumesces a little, and then froths 

 and melts into a greyish globule, giving at the same time some globules 

 of lead. In the oxidating flame, a small quantity effervesces with, and 

 imparts a green color to, borax and salt of phosphorus, which remains 

 transparent on cooling ; but in the reducing flame, the globule turns red 

 and transparent, or red and opake, or finally black, according to the quan- 

 tity of the mineral employed. 



