﻿F. W. Clarke — Lithia Micas. 355 



These results show clearly that the alteration product is not 

 lepidolite but damourite, a fact which could hardly be alto- 

 gether unexpected. The material analyzed was received from 

 Mr. 1ST. H. Perry of South Paris, Maine. 



Norway. — The specimens from this locality were partly col- 

 lected during a field expedition, and partly received from N. H. 

 Perry. The lepidolite was of two varieties ; one, pale brown and 

 very finely granular, the other much coarser in structure and 

 white. Most of the associated tourmaline has a peculiar, dark 

 oily-green tint ; and with many of the specimens a rose red earthy 

 clay was associated. A partial analysis of the latter was pub- 

 lished in Bulletin No. 9 of the U. S. Q-eological Survey, but a 

 re-analysis seemed to be desirable and was therefore made by 

 Mr. Riggs. The results are subjoined and show that the 

 mineral approaches nearly to cimolite. The difference from 

 the earlier analysis indicates a non-homogeneity of composi- 

 tion. As to the genesis of the clay, nothing can be said with 

 certainty. 



Si0 2 66- 



A1 2 3 22- 



Fe 2 3 



FeO ..._ __. 



MnO 



CaO_ 



MgO 



Li 2 



Na 2 



K 2 0. 



H 2 0_ 



F____ 



8G 

 23 

 47 

 18 

 07 

 42 

 33 

 29 

 46 

 18 

 26 

 06 



99-81 

 Formula, Al H SiX> . 



' 2 4 5 15 



Auburn. — In the western part of this town, near the Minot line, 

 there are two localities for lepidolite, less than half a mile apart. 

 The one longest known is small and unimportant, but the 

 other on the farm of Gr. C. Hatch, has been quite thoroughly 

 developed.* It has yielded many gem tourmalines, mostly of 

 the paler tints, some remarkable apatites, and perhaps the best 

 crystallizations of lepidolite so far known. The latter mineral 

 occurs in the ordinary purplish, coarsely granular form and 

 also in extraordinary perfection as a border upon muscovite ; 

 the broad plates of the latter being practically encircled by 

 aggregations of small crystals of the lithia mica. Some speci- 

 mens of this type have also been found at Paris. 



As it was hoped that this mode of occurrence of lepidolite 

 might throw some light upon its genesis, three analyses of 

 Auburn material were made by Mr. Riggs: first, of the com- 

 * See Gr. P. Kunz, this Journal, III, xxvii, 303. 



