228 § L. Penfield—Chemical Composition of Triphylite. 
Laboratory. I have made an analysis of it, but of another and 
slightly different variety, obtained by Messrs. Brush a nd Dana 
since the publication of their paper and from an independent, 
though hoe contiguous deposit. The material was particu- 
larly fresh and free from alteration. 
The results of the analysis are as follo 
(3.) Lithiophilite from Branchville, Cosas color light clove 
brown; specific gravity =8°482. 
I 
1 Mean. Atomic relation. 
P,0O; 45°22 45°22 45°22 P 636 
FeO 3°10 12°92 13°01 Fe 180 be 631 
MnO 31°93 32°12 32°02 Mn 4515 — 
Li,O 9°26 seve 9°2 Li 618 t — +628 
Na,O “28 30 "29 Na O10 fs. 
= 1% ess li 
Gangue "S1 "28 29 Li, 309 — 314 
oe —_—_— Naz 005} ~~ 
In the following table the atomic ratio for 
vgs R(=Fe, Mn, Ca, Mg): R(=Li, Na) 
is given for each of the three above analyses, and also for the 
Grafton mineral as analyzed by me (1. ¢.) and for the lithiophi- 
lite analyzed by Mr. H. L. Wel Is (L C.). 
It E 
Pete ek R 
Triphylite, Posenmeis 7608: : *652 : 652 1-07 0°91 
yo. Mie = : °633 : ‘632 1:00 1:00 
for) 
= 
Xo 
® 
Pu 
Gr ps eg oe : 
Lithiophilite, Branebivle, rae mse 22 BRI G28 
"628 12 032: “680 
All of these approach very closely to ratio 1: 1: 1, required 
by the general formul 
es 
he GES 
S 
oa 
2 
ft) 
—J 
RsP,0, + RyPO, or RRPO,. 
The Bavarian mineral deviates most widely from this, and a 
similar though less pronounced deviation is seen in that found 
at Grafton. In all the five cases, however, it will be observed 
that the required ratio of 1:1% for P: R+R, i is very nearly 
given, as is seen in the following table: 
P R+R; 
Triphylite, Bodenmais, Ls P62 
= Norwich, 2 t 1b0 
Grafton, Por Ge 
Lithiophilite, Branchville, Pentield, 1's *: 4s 
Well li wd 
In order to bring out the relations of the different varieties 
co aera contained in them, and also of these in turn to the 
allied species lithiophilite, the five analyses from which the above 
ratios were obtained are given together in the following table: 
