348 T.8. Hunt on Euphotide and Saussurite. 
7. Smaragdite—The smaragdite or diallage of the euphotides 
appears to have been first examined by Vauquelin, who found 
in a specimen from Corsica with specific gravity 3°0; silica a8 
alumina 21:0, lime 13:0, magnesia 6:0, oxyd of iro n 5%, oxyd of 
chromium 7 5, oxyd of. copper 1‘5= 104-5. (Beudant, Mineralo- 
gie, ii, p. 184). Boulanger subsequently analyzed the diallage — 
from the euphotide of the Fiumalto already described. It had 
a density of 3:10, and gave silica 40°8, alumina 12°6, lime 234, 
os a a ‘2, protoxyd of iron 3°2, protoxyd of manganese ese 1, 
xyd of chromium 2-0, water 5-2=99-4.—(Ann. des Mines, (3), 
vil, 159). 
I have analyzed the grass- ee smaragdite already described 
as occurring in crongih an inch in diameter imbedded in the 
saussurite V1. It w some cree penetrated by the latter 
mineral, and c onttned irregularly disseminated slender prisms 
of hornblen de, sae ently associated with tale. The analyse 
gave as follow; 
CRs s <5. 54:30 
Alonina, | oo oe 4°54 
e, 18°72 
gnesia, 19°01 
Ela OL TOK, 5% 5 one hice) cca ke nk ee ee ee 3°87 
of chromium, * oe “61 
Oxyd of nickel, PRUs ANS EOS traces 
Ss bd 2°80 
tn by ignition, Seti Pee i fee 30 
99° i” 
Tbive 
wa diallages,* gave evidence of a trace of cobal 
blowpipe. The oxygen ratios of the silica, alumina and 
toxyds in the above analysis are as 28°96 : 2°12: 8 
position is Meagoerigch that of a pyroxene, with s nt eae 
“ ss ame and probably of tale. A ori of the - 
eral Som one of the euphotides of Mt. Rose, was nag 
to e antlpan and allowing for a small admixture of saussut mit 
found to have the composition of ordinary tale, being @ BY. 
silicate of magnesia with a little iron and a trace 0 - ¢ di 
gp teemosine —1l. The true euphotide is distinet : 
* This Journal, [2,] xxvi, 237. 
