THE MINERALOGRAPHY OF THE FELDSPARS 239 
HYALOPHANE SERIES 
—-— -Exti net. Angles 
—— Specific Gr 
Indices. Refr 
10 20 30 40 50 60 70 80 90 
90 80 70 60 SO 40 0 20 
les 
Or Barium Restricted Potash Cn 
Orthoclase Hyalopbhane Celsian 
Fic. 8.—Plot of the physical properties of the hyalophane series. The uniform 
character of the curves implies that the orthoclase celsian system is a series of solid 
solutions, and that no chemical compound exists between the components. Data 
taken from Iddings and Winchell. 
