ALUMINA. 



.331 



icr 



Fig. 282, the dioclabdrc of Haiiy, in which tlie replacing tangent planes are broadc 

 Fig. 283, in which two of the replacing planes are much larger than the other two, ijiving 

 the crystal a flattened form ; 



Fig. 284, in which ihc edge between I and I is replaced by the plane t ; 

 Fig. 285, in which the edge between M and I is replaced by the plane z ; 



Fig. 2S2. 



Fi2. 2S3. 



Fig. 285. 



M 



M 



Also Figs. 286, 287, and a modification of the triplantc of Haiiy, Fig. 288. 



M on I 112° 30' 



Fig. 280. 



Fi!». 288. 



M 



/ 



.11 



M on s 135° OO' 

 M on tU^° 34' 

 Mon.r 153° 26' 

 Monz 140° 11' 

 I on I 136° 22' 

 I on s 122° 10' 

 I on t 158= 11' 

 I on z 151° 38' 

 son X 161° 34' 

 r on 2 150° W {Haiiy). 

 Orange Countv. There arc several localities of scapolite in this county. Near West- 

 Point, it is in large, white and compact masses, associated with pyroxene. At Fall hill in the 

 town of Monroe, there is a very compact variety of a white and bluish white colour, and 

 having a flat conchoidal fracture. It is associated with the beautiful lamellar pyroxene, here- 

 tofore noticed. 



At Two-ponds in the same town, there is a remarkable locality of crystallized scapolite. 

 The crystals are white and reddish white, opaque, and sometimes rough. They are often 

 very large, and grouped. One of them is nearly ten inches in length, and five inches in 

 diameter. It is associated with pyroxene, sphcne and zircon. 



The same variety is also found at Greenwood furnace ; wliile that which has been called 

 Meionile, but which is seldom transparent, occurs in the form of minute crystals or grains in 

 limestone at the Two ponds, the Forest of Dean and elsewhere. It is often associated with 

 red calcareous spar. 



