352 Sixth Supplement to Dana’s Mineralogy. 
ar aa = etiating array Si 56-03, Ca 25° 06, Me 17°36, Fe 1:38 
gen ratio for the bases and silica 1 29°09=1 : 202 
ot that acted a re and the other bases 71 
Tremolite and Act aetamr afforded on analysis the follewing results: 1, colorless 
from St, Gothard, G.=2 ; 2, yellowish white columnar from Sweden , G.= 2-930; 
3, re her Goavaracer N. Y,, G.=3:00; 4, greenish white columnar from 
aneetsok, pba G.=3 004; 5, green actinolite from ig ty ae: in the 
Zillerthal, ,in Besa 067; 6, grayish green actinolite from Arendal, in 
i Oa Mg Fe Al ign. 
la. 57°72 13°95 27-45 fr. — 0'338= 9945 
16. 58°38 13°86 26°90 tr. — .034=— 9948 
le 5825 1408 [2733]  ¢r. 0'39=100" 
2. 58:87 11:00 281 tr. 147 0:18=100°01 
3 13°89 25°69 1:36 0°38 0:40= 99°12 
4, 54°71 15°06 23°92 241 —- 3°33= 99°43 
4. Ggn.excl) 5660 1558 2474 248 ——. ——= 
5. 55°50 13°46 22°56 6°25 — 1:29= 99°06 
6. 5677 1356 2148 588 O07  2-20=10086 
The oxygen ratio for the bases and silica oes 1: 2°03—2:09; in 2,1: 200; in 3, 
1: 202; in 4, A: ae in 5; 1+ 3°02 + in 6.1; pe ratio is the s ame therefore, 
as in - : iad evant difference is ‘that in the hornblendice mineral the 
lime is to the ot. $ as 1:8, instead of 1:1, or the ana Ca®Sit-+sMgiSi* 
in place of j8i4 Mes 
Anthophyllite is also a similar bisilicate, having the formula FesBit + 30g" Si2. 
IL. Bisilicates of prot ; — Sesquioryd of iron.—Acmite afforded Rammels- 
(mean of res 
Bi 51-66, Ti 1-11, Pe 28-28, Pe 5-23, Mn 0°69, Na 12-46, K 0-43, ign. 0:39==100°25. 
Tt affords the b oxygen ratio, ~ RR, Si, 1: 1-85: 5°86; or for all the bases and silica 
2°85 : 5°86 Whence the ratio is the pyroxene ratio instead of that of 
eters, ani ie Pee is (Na, Fe)? Si2+-oFeSi?, in which Fe: Na=1:3. G= 
or Ee afforded 
Al Be Pe- > Ma. Os Mig: Na KE 
50°25 «122 22°07 880 140 697 128 929 09410072 
whence = om) en ratio for R, Fe, Sim1-04:1: 408, aa the formula R*5i?+ 
Tehasine i _ ors of each Fe, a and 
erieace 
#e Me Mn Ga Mg Nak ign 
6122 1100 1026 791 19°32 O77 trace. orem 7 
ratio R:#: orchid 3°30 : 2659, and the formula 3R*Si* 
Pes, eS in whch ein: : Ga : ): 
affords the formula "oRP-4 APB, Rammelsberg obtained (mean 
og = ¥e Fe Mn Ga Me Na ign. 
5122 trace. 83°75 780 112 2:08 0-90 1058 O68 O16=9829 
ee ete for the bases and silica is 1: 1°92; and of R:#=1: 
nite and arfvedsonite consist of R®Si? or Bese, in the 
1: LSM ED a ce OES 
that t the wee of protoxyds and silicates of ses- 
iple recognized aot illustrated throughout the 
. 
inot ae Augite from Monte 
smal, co pore rags C= 2-4, Augite from 
* 
