UOVEY, THE FOYER METEORITES 



13 



most abundant have been arranged by Dr. O. C. Farrington 1 in the 

 following order of importance: 



1 . Iron 3. Silicon 5. Nickle 7. Calcium 



2. Oxygen 4. Magnesium 6. Sulphur 8. Aluminum 

 The other elements of particular importance in this connection are 



carbon, chlorine, chromium, cobalt, copper, hydrogen, manganese, 

 nitrogen, phosphorus, potassium and sodium. 



Mineral Constituents. 



Seven elements have been found in meteorites in the elemental or 

 uncombined state. They are iron, nickel, cobalt and copper in the form 

 of alloys, carbon, hydrogen and nitrogen. With these exceptions, the 

 constituents of meteorites are chemical compounds and all but six of 

 the whole list have their exact equivalents in minerals which are found 

 in the crust of the earth. 



According to most authorities the constituents of meteorites may be 

 divided into essential and accessory components as follows 2 : 



Essential. 

 Nickel-iron 

 Olivine (chrysolite) 

 Pyroxenes (Orthorhombic ) 

 Pyroxenes (Monoclinic) 

 Feldspar (Plagioclase) 

 ^Maskelynite. 



Accessory. 

 *Schreibersite 



Diamond 



Graphite (Cliftonite) 



Hydro-carbons. 



Cohenite 

 *Moissanite 

 *Troilite 



Pyrrhotite 

 *Daubreelite 

 *01dhamite 



Tridymite 



Chromite 



Magnetite 



Osbornite 



Lawrencite 



Glass 



'Journal of Geology. Vol. IX, p. 394. 1901. 



2 E.Cohen. Meteoritenkunde I, p. 322. 1894. The asterisk indicates the min- 

 erals which are peculiar to meteorites and are not known to occur in the earth's crust. 



