oS 



THE GEOLOGIST. 



Simple Silicates of 



Alumina \. A ndalusite ov Chiastolite. 



2. Il y unite. 



3. Kaolin. Hydrated. 

 Lime 4. WoUastonife. 



5. Datolife and Apophyllite. Zeolites. 

 jMag^jesia 6. Talc. Generally some Fe. 



7. Steatite. ditto. 



8. Serpentine. Hydrated. Mg often largely 



replaced by Fe. 



Compound Silicates of 



Alumina and Lime .... 9. Wernerite, or Scapolite. Part of Ca gene- 

 rally replaced by jfa, K. 



10. Anorthite. Felspar species ; pai-t of Ca 



generally replaced by Mg, K, ISTa. 



11. Stilbite or Desniine, ffeidandite, Leonhardite, 



Scolezite or calcareous Mesotype, Chaha- 

 site (often with Na), Laumonite, Prehnite 

 (often vn.th. Fe). All zeolites. 



Alumina and Magnesia . . 12. Soajostone. Hydi-ated ; generally with Fe. 



Alumina and Potash . . . 13 Orthoclase. Common, or Potash Felspar. 



14. Leucite. A Felspar species. 



15. Harmotome or Baryta-Harmotome, with 



sihcate of Ba. A zeohte. 

 Alumina and Soda .... 16. AJhite. Soda Felspar, a small portion of 



Na usually replaced by Ca, K. 

 17. Sodalite. Combined with Na CI (Chloride 

 of Sodium). 



IS. MesotypeOT Nat7'olite, Mid Analcime. Zeohtes. 

 Alumina and Ltthia . . . 19. Petalite. Litliia Felspar ; often contains 



Na. 



20. Spodument, or Triphane. A Felspar species ; 



often with Na. 

 Alumina and Per-oxide Iron 21. Staurolife. 



22. Bole. Hydi'ated ; allied to Kaolin, and the 



bases of clays. 



Alumina, Lime, AND Soda. . 23. Oligoclase. A Felspar species. 



24. Lalradoritc. ditto. 



25. Andesine. ditto. 



26. Epistilhiie, Mesolite, Thomsonitc, and Comp- 



tonite. Zeolites. 



Alumina, Soda, and Potash . 27. Sanidine or Adularia. Glassy Felspar. 



2S. Ryacolite. A Felspar species. 



29. Xcpheline. ditto. 

 Alumina, Lime, and Iron . . 30. Epidote. 



Alumina, Lime, Magnesia, ol. Garnet. The mineral is very variable in its 

 AND Iron ^ composition, and has many varieties. The 



proportions of Arl, Ca, and the two oxides 

 of iron vaiy gTeatly. It often contains 

 Mn. 



32. Idocrase or Tesuvian. 

 Alumina, ISIagnesia, & Iron . 33. Cordieritc. 



