Chemical formulas of the Silicates. 257 
The species here included are all of the isometric er: the 
system which is peculiarly defiant of change from orphous 
substitutions; and they are alike of the garnet oetine 
II. Brsrz1catss. 
A. Anhydrous. 
Wollastonite, Si0jO.|R Si0]O.]Ca 
| Bitaite, . Si0]O.|Mg 
paretite, : Si0]O.|Mg 
Griinerite, 4 Si0]0.| Fe 
Rhodonite, “ giO 
Fyroxene . Si0]O,](Ca, Mg, Fe, Mn) 
Hypersthene, “« Si0]0,| (Mg, Fe) 
_ __ Anthophyllite, . Si0]O.|(2Mg+t 4Fe) 
Amphibole, A, “ Si0]0,| (Mg, Ca, Fe, Mn 
* £ - Si0]O2|(m2, Mg, Ca, Fe, Mn)* 
Babingtonite, Si0]0.|(R, BR) SiO] 0.](4(Fe, Mn)+22Fe) 
Beryl : i0]0,](4Be+484l) 
watz SiO] O21, R, BR) SiO] Oo} (A(8a2, R)-+48Fe) 
ichtisite, a SiO] 024 (4(was, R)-+38Al) 
Acnite, “ $i0]Oa](4(xa2, R)+88Fe) 
Arfvedsonite, “ SiO O.](2(sas, R)+38Fe) 
mmene, SiO] 0.4 (za, SiO]G.|( (tis, Nas)-+$P AD) 
Oryophylit hos SiO]. (3(e», tia, B+ 9841) 
Malate Si0{O.1 (2s, B, 7R) Si0 10.4 ¢(82, R)+4722)t 
B. Hydrous. 
Tale, A, SiO] 02] (#2, R) Si0]O.|($#.+ $Mg) 
Si0]O.1(, R)-+nag Si0]0.1(4a,+3Mg)+ 7394 
Sepiolite (Meerschaum SiO] O.| ($a. + #Mg) +489 
ae Si0|0-1 as, BR)--naq Si0]O, [(4o+48A41+3594 
i Si0]O,|(422-+28Al) +404 
: SiO] O24 (m2, R)--naq SiO] O.|(442+4Ca) +34 
— et Si0]0.1(R, 8R)}+naq SiOJO.(2Ca+-46Al)+aq 
“ctolite, Si0] Oa] (sta, Ro, R) SiO Oa] (F1t2-+-§ (842, Ca)) 
Dioptase Si0}O,|R-+naq $i0]O,|Cu-+aq 
Ill. SusstLicaTEs. 
Ro the Subsilicates, the combining power of the silicon is less 
ig that of the basic metal, the oxygen ratios for the 
leon being 3:2, 2:1, 4:3, of which 3:2 is the most com- 
ag The panty 2-eates of aluminum (or of an element in the 
ta state) known among minerals are Subsilicates ; all the Uni- 
ext uch am hibol ter: and according to to Lechartier 1 to 15 p.6 
rp ordinary iccla eapa ther earns, and t ras — a red heat 
expel it, ae the water basic the r : 1 when sat eo withoats 
at ike Siete ae 44d: 2662 
ac * 
vere ea ater ee ae 
