40 B. B. Biggs — Composition of Tourmaline. 



Analyses. 



Analyses have been made of material from the following lo- 

 calities : Auburn, Rumford, and Paris, Maine ; Calhao, prov- 

 ince of Minas Geraes, Brazil ; Dekalb, Gouverneur and Pierre- 

 pont, !N\ Y. ; Hamburg, 1ST. J. ; Orford, IS". H. ; Monroe and 

 Haddam. Ct. ; Stony Point, 1ST. C, and Nantic Gulf, Baffin's 

 Land. These represent well the variations in physical properties 

 and chemical composition which characterize the different va- 

 rieties of tourmaline. The results of these analyses are grouped 

 for the sake of compactness. The tourmalines from Maine and 

 Brazil are thrown together according to localities. Those from 

 other localities are roughly grouped on the basis of their com- 

 position. 



Maine. — These tourmalines occur in veins of albitic granite, 

 the chief constituents of which are quartz, albite and musco- 

 vite, with lepidolite and beryl as important accessories. 



Auburn. — A. Colorless to pale green crystals, some of which 

 were tinged pink and blue ; infusible. G. 3 - 07. B. Light 

 green fragile crystals, infusible. C. Dark green massive tour- 

 maline, fuses with difficulty. D. Massive black tourmaline, 

 easily fusible. G. 3*19. 



I. 



ii. i. 



ii. 





I. II. 



i. ii. 



Si0 2 38-14 — 



38-00 37-85 — 



37-80 



' 36-26 



— 36-98 



34-99 — 34-87 



Al 2 O s 39-60 "1 

 Fe 2 3 -30 [ 

 FeO 1-38 [41 



37-73"| 





36-68"] 





33-96 "} 



■42 ! 

 •37-41-48 3-88 [42- 





•15! 

 54 7-07 f 





none 1 

 3 14-23 [49-76-49-79 



37-42- 



44-65-44-7 



Ti0 2 none J 



none J 





none J 





? J 



P 2 5 trace 



trace 





trace 





trace 



MnO 1-38 



•51 





•72 





•06 



OaO -43 



•49 





•17 





•15 



MgO trace 



•04 





•16 





101 



Li 2 1-34 



1-34 





1-05 





trace 



Na 2 2-36 



2-16 





2-88 





2-01 



K 2 -27 



•62 





•44 





•34 . 



H 2 4-16 4-06-426 4"18 446-4-20 



4-05 4-00-4-11 



362 3-56-3-68 



Bo0 3 10-25 10-15-10-34 10-55 





9-94 i 



3-83-10-04 



9-63 9-44-9-82 



F -62 - 



- -72 -62 — 



•72 



•71 



— -80 



none 



100-23 



10039 



100-28 



100-00 



less oxy. "26 



•26 





•30 

 99-98 







99-97 



100-13 





The material for the abc 



>ve analyses 



was received from Mr. 



K H. Perry 



, of South Pari 



is, Maine. 







Bumford. A. Massive, rose-colored, infusible. G. 2*997. 

 B. Massive, dark green, fuses with difficulty. 



Baris, Black Jit. Massive, black, powder bluish, easily 

 fusible. 



