O 



66 



R n -Silicates l 



Willemite Zn 2 Si0 4 



Spodumene LiAl(Si0 3 ) 2 

 (Sodium Silicate Na2Si0 3 ) 

 Enstatite MgSi0 3 

 Pectolite HNaCa 2 (Si0 3 ) 2 



Amphibole Ca(Mg 3 )(Si0 3 ) 4 



Talc H 2 Mg 3 (Si03)4 



Serpentine HjMgsSi^Og 



Deweylite H4Mg 2 Ni 2 (Si0 4 ) 3 - 

 4 H 2 



Apophyllite (H,K)Ca(Si0 3 ), 

 H 2 



R" '-Silicates 



Topaz (Al,F) 2 Si0 4 



Cyanite (A10) 2 Si0 3 



' Orthoclase KAlSigOg 



Microcline KAlSi s O g 

 Albite NaAlSi 3 O g 



INFRA-RED REFLECTION SPECTRA. 



7JU 8/U 9yU IOjU 



a 



[ Muscovite H 2 KAl 3 (Si0 4 ) 3 

 S ! 



Biotite (H 1 K) 2 (Mg,Fe) 2 (Al,Fe) 2 

 I (Si0 4 ) 3 



Tourmaline (Na,Mg,Al,Fe.) 

 (BOH)(Si0 4 ) 8 



Natrolite Na 2 Al2Si 3 Oio+HtO 

 Datolite CaB 2 (Si0 4 ) 2 



Beryl Be 3 Al (Si0 3 ) 6 



R^-Silicates. 



Zircon ZrSi0 4 



g ["Quartz (crystal) SiQ 2 



-a 



a 

 o 



^ Quartz (glass) 



IIJU 



I2JU 



7fl 8^ 9 ft 



Fig. 46. Line spectra of silicates. 



IOJU. 



IIJJ 



I2,U 



1 R", Valence of metal is indicated by the exponent. 



