Mineralogy and Geology. 269 
ar. Incl. 
24. ee Finland. Rhombic octabedrons; a yee clear blonde, APT 68° 
25. and. ed hasan ent ah grayish gree 67-68° 
27. Aberd Transparent; blonde, 68° 
28. Pec deicnberg, Rhombic prisms in feldspar gee “te nearly blonde, 6 Fads 
a central reg 
29. Loc. ? Colorless; but affords | gh adtat te ey so 
8 —— probably; Lepidolite or rose mica 74-769 
33. Alencon. Hexag.; transparent; grayish blonde, 6-717° 
(2.) Micas with the optical aves in the diametral plane of the shorter 
diagonal. 
4, Lake Baikal. Hexag.; deep brown; transparent, 
35, 36, aT, AS at —micas aS “unkno wn localit ity, i- 4° 
» Loe deep bottle green 15° 
40, Saxon tities se , clear ansp., macled, 44° 
42. Zinnwald, with tin ore. Hexag.; : on. gris iidenle by trp., 46-47° 
43, ? Hexag.; transparent; colorle 50° 
44, Lepidolite ; bio 55° 
46. Piedmont. hombic ; silvery reflection; grayish green by trp., 63° 
48. St. Féréol, near Briv ves, Transparent ; olive-gre en, 65° 
49.. Milan, ag.; greenish-white ; silvery ; unctuous, not elastic, 5° 
51, Fossum, Norway. Hexag.; clear olive-green, 66°. 
52, Scotland. Brown; in large thick crystals, yes 
4. Tarascon (Ariége). Rhombic; pi sore get 
55. Ural, in graphic granite ; octahedrons in quartz; silv. ee col. Sead n° 
56. Uté. Rhombs; lustre silvery ; eae oie by trp. 2-18? 
On examining different micas pressed between two plates of oa 
and subjecting them to changes s of Rian My there was no percepti- 
ble change in the optical axes. 
On Mica and Cordierite, especially upon poye Chloritoid, Pearl 
mica, Kémmererite, Rhodochrome, Baltimorite an d Chrome-chlorite ; by 
r 
ing 
P : 
of the author, phlogopite, with Meitzendorff’s formula, and muscovite, 
binati c 
=r Fe. 
a oa so72 1728. 1780 a6 ae 
1271 14:33 
a 8268 26-38 18-95 es 139 450 G.=3'46 
Oxygen 16°96 1228 567 357 0 
ga 32°46 4018 1°34 Ca 742 3°21 43% i008, Nar em, G=2:99 
Oxygen 1681 2296 040 2121 127 4 
* From Katherinenberg. 
