AO ' 



n 



a (i 



AL 



( i 



{ i a 



AW " 



1 1 



1 1 , a 



AB 



i c 



n t ( 



AD 



t i 



it ( ( 



AE 2 " 



( i 



a < ( 



178 Ferguson and M,erwin — The Ternary System. 



inserted if the diagram were exactly a representation of 

 the facts as we have found them; also in those cases in 

 which the results obtained were insufficient to indicate 

 the exact relations we have chosen what appeared to us 

 the most probable interpretation. Thus we show wollas- 

 tonite taking up a little more diopside in solid solution 

 than does pseudowollastonite, although our evidence is 

 only sufficient to indicate that the limits lie close together. 

 The meaning of the symbols, etc., upon the diagram, 

 is as follows: 



AP represents the solid solutions of wollastonite and silica. 



" wollastonite and 3Ca0.2Si0 2 



" pseudowollastonite and 3Ca0.2Si0 2 



11 pseudowollastonite and diopside 



li wollastonite and diopside 



" wollastonite and akermanite 



' ' pseudowollastonite and akermanite 



The areas of solid solution are indicated by the shaded 

 portions of the figure. The arrows show the directions 

 of falling temperatures. The field, 14, 15, 16 corresponds 

 to the solid solution B, the field 14, 16, 1, H, 13 to the 

 solid solutions ranging from C to F, and the field 13, 

 H, 3, to the solid solutions ranging from C to T. The 

 locations of F and T are known only approximately. T 

 may or may not be between C and the boundary 13 J, and 

 for simplicity we have placed it at the point of inter- 

 section of the boundary by CD. F is the solid solution 

 stable at point 14, M the solid solution stable at 16, and 

 N the solid solution stable at 1. C, the 5Ca0.2MgO. 

 6Si0 2 compound, is stable along the line 13H, where H 

 is the determined maximum on the line 1, 3. T is the 

 solid solution stable at 3 and R^ is the solid solution of 

 pseudowollastonite stable at 13. ~R 1 is arbitrarily loca- 

 ted and may or may not coincide with R 2 . The pseudo- 

 wollastonite solutions extend throughout the area AWR 2 

 and W may be in the position indicated or may coincide 

 with B or be just on the other side of it. The decompo- 

 sition temperatures of B and F are the same as the melt- 

 ing temperature of point 14, about 1340 °C, and the 

 decomposition temperature of C the same as the melting 

 temperature of point 13. The latter has been the more 

 carefully determined and is 1365 °C. 



"With the aid of this diagram the products resulting 

 from the crystallization during cooling under equilibrium 

 conditions of the various compositions lying within the 

 pseudowollastonite field may be worked out and the 



