Mineral Synthesis. i6i 



ical and miiieralogical synthesis was long overlooked. In 

 the chemical sense, if the artificial product has the definite 

 chemical composition, reaction, and physical properties, 

 as density, boiling point, etc., the synthesis is complete. But 

 in mineralogical synthesis, in addition to this, there must be 

 entire agreement of the resulting product with the natural 

 one morphologically. It must have the crystal form and also 

 the characteristic type as in nature, with the optical and physi- 

 cal properties to be perfect. As an illustration, the elements of 

 orthoclase might be fused, and the resulting product have the 

 physical properties and composition of the mineral, but this 

 could not be termed a mineralogical synthesis unless the 

 crystal form be produced. 



In order to make a perfect synthesis, certain conditions 

 must be fulfilled: 



1. The artificial mineral must possess the chemical compo- 

 sition of the natural one. 



2. The new mineral must belong to the same crystal sys- 

 tem, \\\\.\\ like forms and crystallographic parameters. The 

 analogy should even be followed in the twins and the devel- 

 opment of certain common faces. 



3. The identity must be continued in the internal structure, 

 as revealed by the microscope — in optical properties, cleav- 

 ages, inclusions, and mode of alteration. 



4. The mineral should also show the associated minerals 

 occurring in the rock and in the same mode of association. 



5. There must, through the whole process, be a perfect 

 agreement of the conditions of the experiment with those 

 supposed to exist in the natural origin. 



6. When all these conditions are fulfilled, it is very probable 

 that we have employed the exact means which held in the 

 natural process. As a final control comes the geological 

 examination as to association, etc. 



Under the head of artificial minerals we must exclude those 

 accidentally formed in the industrial works ; as, graphite on 

 the walls of iron furnaces, for such do not answer the question 

 of the origin of such minerals, for the reagents and conditions 

 remain unknown. Nevertheless, the recorded observations of 

 such products have aided reproduction in the laboratory. 

 Such observations have been noted especially by German 



