FREE BOOKS

Author's List




PREV.   NEXT  
|<   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46  
47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   >>   >|  
f W. Luzi, who found that it can be corroded by the solvent action of fused blue ground; from the experiments of J. Friedlander, who obtained diamond by dissolving graphite in fused olivine; and still more from the experiments of R. von Hasslinger and J. Wolff, who have obtained it by dissolving graphite in a fused mixture of silicates having approximately the composition of the blue ground. E. Cohen, who regarded the pipes as of the nature of a mud volcano, and the blue ground as a kimberlite breccia altered by hydrothermal action, thought that the diamond and accompanying minerals had been brought up from deep-seated crystalline schists. Other authors have sought the origin of the diamond in the action of the hydrated magnesian silicates on hydrocarbons derived from bituminous schists, or in the decomposition of metallic carbides. Of great scientific interest in this connexion is the discovery of small diamonds in certain meteorites, both stones and irons; for example, in the stone which fell at Novo-Urei in Penza, Russia, in 1886, in a stone found at Carcote in Chile, and in the iron found at Canon Diablo in Arizona. Graphitic carbon in cubic form (cliftonite) has also been found in certain meteoric "irons," for example in those from Magura in Szepes county, Hungary, and Youndegin near York in Western Australia. The latter is now generally believed to be altered diamond. The fact that H. Moissan has produced the diamond artificially, by allowing dissolved carbon to crystallize out at a high temperature and pressure from molten iron, coupled with the occurrence in meteoric iron, has led Sir William Crookes and others to conclude that the mineral may have been derived from deep-seated iron containing carbon in solution (see the article GEM, ARTIFICIAL). Adolf Knop suggested that this may have first yielded hydrocarbons by contact with water, and that from these the crystalline diamond has been formed. The meteoric occurrence has even suggested the fanciful notion that all diamonds were originally derived from meteorites. The meteoric iron of Arizona, some of which contains diamond, is actually found in and about a huge crater which is supposed by some to have been formed by an immense meteorite penetrating the earth's crust. It is, at any rate, established that carbon can crystallize as diamond from solution in iron, and other metals; and it seems
PREV.   NEXT  
|<   22   23   24   25   26   27   28   29   30   31   32   33   34   35   36   37   38   39   40   41   42   43   44   45   46  
47   48   49   50   51   52   53   54   55   56   57   58   59   60   61   62   63   64   65   66   67   68   69   70   71   >>   >|  



Top keywords:

diamond

 

meteoric

 
carbon
 

action

 

ground

 

derived

 

crystallize

 
suggested
 

formed

 

schists


seated

 

altered

 

occurrence

 
silicates
 
graphite
 

hydrocarbons

 

dissolving

 
obtained
 

experiments

 

crystalline


Arizona
 

meteorites

 
solution
 

diamonds

 

Crookes

 

William

 

dissolved

 

generally

 

believed

 
Western

Australia

 

Moissan

 

temperature

 
pressure
 

molten

 
produced
 
artificially
 

allowing

 

coupled

 
immense

meteorite

 
penetrating
 
supposed
 

crater

 

metals

 

established

 

originally

 
ARTIFICIAL
 
article
 

conclude