268 Brush and Dana—the Spodumene of Branchville, Conn., 
Two analyses of cymatolite have been made by Mr. Penfield. 
Number 1 was made from a portion of an entirely altered 
rystal; it was perfectly white and prenpenhyy free from any 
impurities. The results are as follow 
No. 1, G.==2°692. I. Il. It, Mean. Ratio. 
Si0.  - 59°38 aes Se 59°38 
Al,O; 26°67 nee Aus 26-67 259 1-05 
Cad 0-6 on iil 0-62 oll 
Wage (ie 7-66 7-70 1-6 124| 
K,0 ee 3:53 3°49 3-51 os7f 288 «IIB 
H,0 201 ne ae 2-0 111 
99°87 
The second analysis was made on the pure mineral associated 
on the same crystal, which Sei Sage 2 of 8 spodumene. 
The results afforded are, as follow 
No. 2, G.==2°699. I. Mean, Ratio. 
iO» 60°61 wis 60°55 1009 4 
Al,03 37 26°39 26°38 256 1-016 
0-08 0-06 
Na.0 8-08 8°16 8-12 131 
3 3:33 3°35 3°34 o35| 
Li,O 7 0-17 0-17 006 2631044 
HO 1°65 1-66 1°65 091 
100°29 100°28 100°28 
The agreement between these two analyses is as close as 
could be expected ; the ratio obtained from No. 2 is nearly 
R,0: Al,O3: Si0g = 1:1: 4. 
This is the same ratio as that _ for spodumene and f 
spodumene. The formula is therefor 
(Na, K, H),A1,$i,0,.—=(K, sith i cuabeoet 
Since the cymatolite is certainly derived from the # spodu- 
mene, while the latter substance has been proved to be a mix- 
ture of albite and what—as was shown—has the composition 
of a lithia siaiboyite the fact that the formula of cymatolite can 
be written as a compound of one molecule muscovite and one 
molecule albite is significant. Were no other facts at hand the 
conclusion that cymatolite also must be a mechanical mixture 
could hardly be questioned. The facts, however, are in them- 
selves sufficient to prove this, inde endent of any other consid- 
erations. It may be mentioned that the chemical method of 
attacking the problem, employed in the case of the # spodu- 
mene, is not here applicable, since the muscovite is not decom- 
posed by hydrochloric acid. preliminary examination was 
made with sulphuric acid, which resulted in showing that the 
cymatolite was attacked by it, as was the mica of the locality, 
eee the albite was barely so. This method was, however, 
carried further, for the microscope gave all the solution 
shat could be desired. 
