i 
N. von Kokscharov on the Clinochlore of Achmatowsk. 179 
ie ee a kk (over P) 47° 25/ yo 145° 57! 
v2 150° 10’ tP 108° 14/ yk 22° oe 
vt 150° 597 th 161° 46’ aged gt ig 
wh 1479 1? tt (over h) 148° 337 zt 148° 127 
vv 65° 57! éP 108° 58/ zy 129° 59! 
KP 118° 49° io 150° 44’ 2P 125° 7 (125° 4/#) 
kh 156° 18' in 148° 35’ tM 151° 45’ 
k (over h) 132° 35! iy 161° 47/ 
For the forms, X, Y, Z, etc., have the following values: 
es Bs Z i Q o 
Form % 68°57’ 62°41’ 61°28" 59°17’ 57°59’ 60°29’ 60°00 
= 19 2 
w-3 32 59 
3-0 23 42 66 18 
40 18 14 71 46 
1-c 41 04 6 05 
oe 59 17 BT 52 
4-c9 o 16. 10iaee 
4-0 7 5T 54 53 
Cleavage very perfect parallel with the base. G.=2-774 accord- 
ing to G. Rose. H.=2-5. Strongly dichroic, being green in the 
direction of the vertical axis and brown or hyacinth-red trans- 
versely, and the colors seldom so different in other dichroic spe- 
cles, Streak-powder light greenish-white. The largest crys- 
tals often only translucent on the edges; the smaller subtrans- 
Parent. Flexible in thin plates buat not elastic. ie 
_ Although the basal plane is usually smooth and shining, there 
IS in some crystals an unevenness which indicates by its stellate 
appearance a regular composition. In the erystals of Achma- 
towsk, this compound structure is quite common ; 
Since the faces of the form 2 are inclined to the clinodiagonal sec- 
ton 60°, and to the basal plane 89° 43’, the three erystals will 
Meet at angles of 60°, and have their basal planes inclined to one 
another 179° 25/, or very near 180°.t The large erystals are often 
So made up of a mixture of small crystals with their basal planes 
Srouped in rosettes, as happens in the specular iron of St. Gothard. 
* Observed angle. : 
t It might be suspected from such twins which 
the plane §P may make an angle of 90° with the 
vius); but the appearance of salient and reéntering ang g 
are like those of Aragonite, that 
t 
base, {as in the mica of Vesu- 
