THE MINERALOGRAPHY OF THE FELDSPARS 253 
2 & 
ke) 
ESS 
POTASH/POTASH 
OLIGO. /ANDESINE 
C«Fetp 
Fic. 13.—Proposed schemes for classification of the potash-soda-lime feldspars. 
The upper diagram is the “‘technical’’ while the lower one is the “popular” scheme. 
Orthoclasic feldspars are not indicated; the microclinic forms being shown instead. 
