CHAPTER II 

 THE ORIGIN OF MINERALS 



TIIK origin of all minerals must have been from solutions and 

 gases, or the result of the interaction of these on minerals previously 

 separated from solution. It is of very little difference whether the 

 solution is one of water or of fused silicates, homogenous and fluid 

 only at high temperatures. In either case the same laws will 

 apply, and the same physical and chemical laws will hold true 

 whether that solution is but a thimbleful of silicate fused in the 

 electric furnace of the laboratory or contained in the enormous 

 crucibles of nature. Practically the same conditions can be du- 

 plicated in th-3 laboratory with the exception of time and pressure. 

 Time is the factor so essential for the formation of large and per- 

 fect crystals. 



Most minerals, at least the common species, have been synthe- 

 sized or artificially produced in the laboratory. The exception is 

 a class of minerals which it is believed have been formed under pres- 

 sure and in the presence of water, or they belong to that class which 

 are produced by contact metamorphic conditions, in most cases, 

 as the micas, epidote, topaz, vesuvianite, and amphibole. The 

 artificial products lack water in their constitution, and therefore the 

 conditions under which they were, formed in nature have not been 

 reproduced or duplicated in case of the artificial product. 



Indeed the conditions surrounding the crystallization of any 

 mineral in nature must be excessively complex. The conditions 

 under which individual minerals may form as conditioned by tem- 

 perature, pressure, and other components in the system have been 

 studied in but few cases, and in these the result has been the dis- 

 covery of unknown, unsuspected phases, which have been of great 

 assistance in the explanation of the various isomorphous series, 

 containing the same elements but of different symmc* r\ . 



In order to arrive at some small conception of the importance and 

 influence of one compound or component in solution on the separa- 

 tion or crystallization of another component of the same system, it 

 is probably best to illustrate by a system in which the relations are 



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