ORDER IV. BHOMBOHEDRAL EMERALD-HAL. 171 



hedral Lime-haloide, &c. In veins it is generally found 

 in the higher levels. 



4. Most beautiful varieties, particularly crystallised ones, 

 have lately been found in a bed in secondary mountains at 

 Chessy near Lyons in France. Also in Siberia, very fine 

 crystals have been obtained. Those from the Bannat, 

 though of a smaller size, are often very distinct. Fine 

 crystallised varieties occur at Wheal Buller, near Redruth 

 in Cornwall. Prismatic Azure-malachite occurs, besides, 

 at Saalfeld in Thuringia, in Mansfeld, in Hessia, in "Wur- 

 temberg, in the Hartz, in Silesia, at Schwatz in the Tyrol, 

 in Spain, Chili, &c. The earthy blue copper is chiefly 

 known from Thuringia, Hessia, and from the Hartz. 



5. Wherever it occurs in sufficient quantities, it is an 

 useful mineral for extracting copper. 



GENUS V. EMERALD-MALACHITE. 

 1. RHOMBOHEDRAL EMERALD-MALACHITE. 



Rhombohedral Emerald Copper or Dioptase. JAM. Svst. 

 Vol. II. p. 347. Rhomboidal Emerald-Malachite. 

 Man. p. 100. Dioptase. Emerald Copper. PHILL. p. 

 312. Kupfersmaragd. WERX. Hoffm. H. B. III. 2. 

 S. 158. Dioptas. HAUSM. III. S. 1032. Kupfer- 

 Smaragd. LEONH. S. 288. Dioptase. HAUY. Trait^, 

 T. III. p. 136. Cuivre dioptase. TabL comp. p. 91. 

 Traite, 2de Ed. T. III. p. 477- 



Fundamental form. Rhombohedron. R = 126 

 17'. Vol. I. Fig. 7. PHILL. 

 a = V 0-8413. 



Simple forms. R + 1 (r) = 95 48' ; P + oo (s). 



Char of Comb. Rhombohedral, as to the simple 

 forms observed, but the striae upon the faces of 

 R seem to indicate a hemi-rhombohedral cha- 

 racter. 



Combination. 1. R. P + oo. Fig. 118. 



