32 PEOCEEDINGS OP THE NATIONAL MUSEUM vol.71 



A sample of scapolite from Italian Mountain was analyzed by 

 Eakins with the following results: 



Analysis of mizzoniie 



SiOs 57. 55 



AI2O3 . 21. 53 



FeaOs Trace. 



CaO 6. 18 



K2O 1. 64 



NasO 7.43 



H2O 3.23 



CI 2.82 



100. 38 

 O equivalent to CI . 63 



Total 99. 75 



The only data on which specimen of the several described above 

 was used for the analysis is furnished by the statement that the ana- 

 lyzed material came from a gulch on the east side of Italian Moun- 

 tain. It is presumed that the material first described, being the most 

 showy and purest appearing, was selected for analysis. In this case 

 the analyzed material doubtless contained an appreciable amount of 

 zeolites, particularly scolecite, which would account for the high- 

 water content shown. 



QUARTZ 



Quartz is rare and occurs in small crystals. The barite crystals 

 of the barite specimen rest upon a crust of normal prismatic quartz 

 in minute crystals. A few minute crystals of quartz of ordinary 

 prismatic habit rest as a later deposit on the crusts of albite crystals 

 of some of the specimens which contain pinkish albite in seams in 

 diorite. 



One specimen of albite is overlain by a few quartz crystals which, 

 v/hile minute and poorly developed, have such a peculiar habit as to 

 merit notice. These have certain faces suppressed, giving them a 

 habit so like topaz to lead to their being mistaken for that mineral 

 until the crystal angles and optical properties had been measured. 

 Two of the crystals which were measured are represented by Figures 

 14 and 15, the forms being tentatively identified as those of quartz 

 by comparison with the angles of the Winkeltabellen. Actually the 

 crystals are much less perfect than indicated in the figures, since, 

 although the faces give good signals, the interfacial angles are largely 

 replaced by rounded etched areas. 



SCOLECITE 



Although in no case forming good or attractive mineral speci- 

 mens, the comparatively rare zeolite scolecite is the most common and 



