MINERALOGY, 



513 



Oryctogno- and various ores of copper. 

 7- Cornwall. 



It occurs principally in 



Earthy 

 Acicular 



Ulirenite. 



Htxabe- 



nitr. 



FOURTH SI-BSPECIES. 

 EARTHY ACICULAM OLIVENITE, Jameson. 



External Characters. Colour olive-green. Occurs 

 massive, disseminated, and in crusts. Dull. Fracture 

 fine earthy. Sometimes occurs in concentric lamellar 

 distinct concretions. Opaque. Soft and very soft. 



Geognottic and Geographic Siluatioitt.^ll occurs 

 along with the other subspecies of olivenite in the cop* 

 per-mines of Cornwall. 



IV. HEXAHEDRAL OLIVENITE, or CUBE-ORE, Jame- 

 son. Wurfelerz, Werner. 



Tessular. Cleavage hexahedral. Streak olive-green ; 

 brown. Hardness = 2.5. Sp, gr. = 2.93.0. 



External Characters. Colour green. Occurs mas- 

 sive ; and crystallized in the following figures : 



1 Perfect cube. 2. Cube, in which four diagonally 

 opposite angles are truncated. 3. Cube truncated on 

 all the edges. 4. Cube truncated on all the edges and 

 angles. 



Crystals small and very small, and always superim- 

 posed and in druses. Planes of the crystal* smooth 

 and splendent. Internally glistening, and lustre inter- 

 mediate between vitreous and resinous. Fragments 

 indeterminate angular, and rather sharp-edged. Trans- 

 lucent, or translucent on the edges. Streak straw- 

 yellow. Rather brittle, and easily frangible. 



Chemical Charactert. Before the blowpipe it melts, 

 and give* out arsenical vapours. 



Constituent Parts. Arsenic Acid, 31.O 



Oxide of Iron, 45.5 



Oxide of Copper, 9.0 

 Silica, . . 4.0 

 Water, . . 10.5100 

 Chenetix, in Phil. Trans, for 1801. 



Geognottic Situation. It is found in veins, accom- 

 panied with ironshot quartz, copper-glance or vitreous 

 copper, copper-pyrites, and brown iron-ore. 



Geographic Situation. It occurs in Tincroft, Carra- 

 rach, Muttrel, Huel-Gorland, and Gwenap mines in 

 Cornwall. 



Aucamite. "ATACAMITE, OR MURIATE OF COPPER, Jameson. 

 Salzkupfererz, Werner. 



This species is divided into two subspecies, viz. 

 Compact and Arenaceous. 



FIRST SUBSPECIES. 



Compact COMPACT ATACAMITE, OR MURIATE or COPPER t, 

 Autamite. Jameson. Festcs Salzkupfererz, Werner. 



External Charactert. Colour green. Occurs mas- 

 sive, disseminated, imperfect reniform, in prismatic 

 distinct concretions, which are short, small, and scopi- 

 t'orm, also in granular concretions ; in crusts or invest- 

 ing ; and in short needle-shaped crystals, of the fol- 

 lowing forms : 



1 . Oblique four-sided prism, bevelled on the extre- 

 mities } the bevelling planes set on the acute lateral 

 f-dges. 2. The preceding figure, in which the acuter 

 lateral edges are deeply truncated, thus forming a six- 

 sided prism. 



Oryctogno- 

 sy. 



Internally shining and glistening, and pearly. Has 



an imperfect cleavage. Fragments indeterminate an- ^ 



gular. Translucent on the edges. Soft. Brittle, and ' ""V" 

 easily frangible. Specific gravity, 4.4 ? 



Chemical Character. It tinges the flame of the blow- 

 pipe of a bright green and blue, muriatic acid rises in 

 vapours, and a bead of copper remains on the charcoal. 

 It is soluble in nitric acid without effervescence. 



Constituent Partt Oxide of Copper, 73.0 

 Water, . 16.9 



Muriatic Acid, 10.1100.0 

 Klaproik, Beit. b. iii. s. 200. 



Geognostic and Geographic Situation. It occurs in 

 veins in Chili ; also at Vimeberg near Rheinbretenbach 

 on the Rhine, and at Schwartzenberg in Saxony. In 

 the fissures of the lavas of Vesuvius, particularly those 

 of the years 1804 and 1805. 



SECOND SUBSPECIES. 



ARENACEOUS ATACAMITE, OR COPPER-SAND, Jams- Arenaceous 

 ton. Kupfersand, Werner. 



External Charactert. Colour grass-green, inclining 

 to emerald-gre*n. Occurs in scaly .particles, which < 



are shining, glistening, and pearly. Does not soil. 

 Translucent. 



Cmttit. Parti Oxide of Copper, 70.5 



Water, . . 18.1 

 Muriatic Acid, 11.4 



100.0 



Proutl, Journ. de Phys. t. 50. p. 63. 



Geognottic and Geographic Situations. It is found 



in the sand of the nver Lipes, 200 leagues beyond 



Copiapu, in the desert of Atacama, which separates 



Chili from Peru. 



EMERALD 

 COPPER. 



GENUS IV. EMERALD COPPER. 



Smaragd- Malachite, Muhs. 

 One axis. Cleavage rhomboidal. Streak. Hard- 

 ness = 5.0. Sp. gr. = 3.3, 34. 



This genus contains but one species, viz. Rhomboidal 

 Emerald Copper, or Dioptase. 



1. RHOMBOIDAL EMERALD COPPER, or DIOPTASE. Hhombol- 

 Jameson. RhomboedrischerSmaragd-Malachite, Mofis. d.ii Erac- 

 Kupfer-Schmaragd, Werner. "Id Cop- 



Rhomboid = 123 58'. Cleavage rhomboidal. P r ' 



External Character*. Colour emerald green, which 

 sometimes inclines to pistachio and blackish green. 

 Occurs only crystallized. The only secondary form at 

 present known, is the cqui-angular six-sided prism, 

 which is rather acutely acuminated on both extremities 

 by three planes, which are set on the alternate lateral 

 edges. Lateral planes smooth. Internally shining, 

 and lustre pearly. Fracture small conchoidal. Trans- 

 lucent, passing to semi-transparent Brittle, and easily 

 frangible. 



Chemical Characters. It becomes of a chesnut- 

 brown colour before the blow-pipe, and tinges the 

 flame green, but is infusible; with borax it gives a 

 bead or globule of copper. 



Constituent Parti. Oxide of Copper, 28.57 

 Carbonate of Lime, 42.85 

 Silica, . 28.5799-99 



Vatuptelin, in Haiiy, t. iii. p. 137. 



t We pUee this mineral immediately after the Genus Olirenite, on account of iu resemblance to it ; but want of accurate information 

 prerenu ui from including it at a specie* of that genus. 



VOL. XIV. PART II. 3 T 



