264 copper. 



than calcareous spar. Before the blow -pipe with borax, it yields 

 a globule of copper. Its specific gravity is 2*5. It consists, accord- 

 ing to Chenevix, of 58 oxide of copper, 21 of arsenic acid, and 

 21 of water. 



Trihedral Arseniate of Copper occurs massive, and crystalized 

 in irregular octahedrons, tetrahedrons, and in acute rhomboids. Its 

 colour is deep blueish-black, with a shining lustre. The specific 

 gravity is 4-2. It consists of oxide of copper 54, arsenic acid 30, 

 water 16. Chenevix. 



Prismatic Arseniate, or Oliven Ore. The colour of this variety 

 is olive-green or blackish-green. It occurs crystalized in small 

 acute octahedrons; also granular and capillary. The specific 

 gravity is 42. Its constituents arc, oxide of copper 60, arsenic 

 acid 397. 



Wood Copper, or Fibrous Oliven Ore, occurs of various shades 

 of brown, green, and yellow, and is found incrusting other arsenites 

 of copper, and also in mamillated concretions. It consists- of 50 

 oxide of copper, 29 arsenic acid, and 21 of water. 



Amianthiform Arseniate of Copper has usually a blueish or 

 grass-green colour. It occurs in fine parallel or diverging flexible 

 fibres, or in plates. Tts chemical composition is the same as that 

 of the preceding variety. 



Martial Arseniate of Copper is of a pale blue or greenish-blue 

 colour. It occurs crystalized in minute rhomboidal prisms, which 

 are sometimes grouped in globular concretions. The lustre is 

 vitreous. It is transparent, or translucent, and harder than cal- 

 careous spar. Its constituents are, oxide of copper 22'5, oxide of 

 iron 27'5/arsenic acid 23, water 12, silex 6. Chenevix. 



Sp. 10. Prismatic Olivenite, or Phosphate of Copper. 

 Pl. XXXVI. fig. 4.— Phosphorkupfererz, Werner; Cuivre phos- 

 phate, Hamj.—Thc colours vary from emerald-green to blackish 

 or yellowish-green. It occurs massive, reniform, in fibrous dis- 

 tinct concretions, and crystalized in oblique four-sided prisms. It 

 is opaque, translucent, with a vitreous lustre, inclining to pearly. 

 The fracture is splintery ; the fragments wedge-shaped, splintery, or 

 indeterminate angular. The streak is verdigris-green ; it is brittle, 

 and easily frangible. Before the blow-pipe it melts into a brownish 



