316 PHYSIOGRAPHY. CLASS u. 



2. RHOMBOHEDRAL EMERALD. 



Rhomboidal Emerald. JAM. Syst. Vol. I. p. 92. Man. 

 p. 191. Beryl. Aquamarine. Emerald. PHILL. p. 102. 

 104. Smaragd. Beril (excepting Schorlartiger Beril). 

 WERN. Hoffm. H.B. I. S. 596. 604. Smaragd. HAUSM. 

 II. S. 655. Smaragd. LEONH. S. 502. Emeraude. 

 HAUY. Traite', T. II. p. 516. Tabl. coinp. p. 31. 

 Traite, 2de Ed. T. II. p. 504. 



Fundamental form. Rhombohedron. II = 104 

 40'. Vol. I. Fig. 7. R. G. 



Simple forms. R oo (P) ; R (s) ; R (s) ; 

 R + oo(ra); P (0 = 151 9', 59 47'; P 4- 1 

 ( M ) = 135 34',98 2'; P + oo (M) ; (P 2) 5 ; 



(P) 1 () 



Char, of Comb. Di-rhombohedral. Z (R) = 138 



4T, 89 45 r . 

 Combinations. 1.R oo. P-fco. Zwiesel, Bavaria. 



2. R CD. P. P + oo. Sim. Fig. 112. Siberia. 



3. R x. R -f oo. P -|- x. Schlaggenwald, 

 Bohemia. 



4. R OD. 2 (R). P + oo. Peru. 



5. R OD. P. 2(R). P + 1. P + oo. 

 Vol. I. Fig. 60. Peru. 



6. R oo. P. 2 (R). P + 1. 2 (R)^. 

 P + OD. Fig. 150. Siberia. 



Cleavage, R oo and P+oo, the first generally 

 more easily obtained, the second interrupted. 

 Fracture conchoidal, uneven. Surface^ the prisms 

 striated parallel to the axis, seldom smooth. The 

 rhombohedrons and pyramids smooth. P oo 



