i Ee ee ee 
si vee 
cemecatc nnn eee 
. 
Mineralogical Notices. 253 
3. Diallage of the Euphotide of Odern.—The diallage is in 
olive green ‘crystalline lamella. It fuses before the blowpipe 
with very great difficulty, much greater than the feldspar associ- 
ated with it. It atfo rded 
1 g ign. 
49°30 pl 030 943511543 in 085==98-93 
Delesse observes that it approaches hornblende, especially that 
from Nordmark analyzed by Bonsdorff. The chromic acid he 
believes to be chemically combined in the mineral. Hededuces 
the formula Rs Siz, which is the formula of the species pyrox- 
ene. ‘The oxygen for the protoxyds, peroxyds and silica equals 
13-51 : 2-66 : 25-61; and supposing the alumina to replace the 
silica, the ratio 1: 2, characteristic of pyroxene, is given. This 
ratio is more exact when silica and alumina replace one another 
in the ratio of 341: 28i. 
4. Talc of the Odern Euphotide—This talc is in imperfectly 
radiated translucent lamelle, often more than a centimetre in 
length, and constitutes hee masses s which cut like a ite 
stone. Compositi on :— Eh 
Bi fe fin oa ‘Me (ait) gas F 
5761 O81 B85 0G. BBS. 841 3°78=100 - ‘* 
This result shows, Delesse observes, that it is near that from . 
Little St. Bernard, a ee by Berthier, and may be re ited 
by the pyroxene formul a R3 Siz: aes i 
he oxygen of the peta yc and silica equals 129 
(=1: 2°38) with 0°38 for that of the alumina. The ‘ 
responding is 3 : 7, (the alumina being excluded, ) which eine. - 
alent to Mgo Sir. The ratio 4: 9 (=1: 2-25) which differs bit lit-#  * 
tle from the result, affords the formula Mg Sis, which ape been* . a 
found for other varieties of tale. . * 
5. Serpentine of the Euphotide of Odern.—The sscialt is ‘*® 
Sometimes in veins as if subsequently filled into fissures,’ and — 
Sometimes in nodules within feldspar, or so graduates into feld- + 
Spar that it seems to have been formed at the expense-o "this ¥ 
mineral or of the euphotide as a whol e, bya spnorobael > 
morphism. Ls 
6. Hornblende of the Diorite of Pont Jean, valley of tha’ o-"= 
- Selle, near St. Maurice in the Vosges. —This me ga is ga, 
é wa 
and of a fine — color and forms lamellar m 
Composition 
Si x ‘Mn Oa Mg (diff) _ Na’ ae 
5004 2895 O24 959 020 1148 1802 | 059=100 al 
The soda.is attributed to Fadaper which : xi 
eral with a lens. ¢ Pe. : x 
eldspar, of the Diorite of Pont’ ea 7 e ist 
idted. with @°: peal feldspathic” Paste™cont 
