Mineral Synthesis. 



63 



diamond, liquid inclusions which would be altered by high tempera- 

 tures, thus showing that diamonds in nature were formed at 

 temperatures but little different from the ordinary. The artificial 

 reproduction is reported as realized by Kannay, but as the secret is 

 carefully guarded, the success is not known. 



Emeralds were produced in 1848, by Ebelmen, by heating at high 

 temperature a mixture in varying proportions of boric acid and 

 pulverized natural emerald with a small addition of oxide of chrome. 

 The resulting crystals were small hexagonal forms with a green color. 



Melanite garnet (calcium) was formed in 1808, by Klapproth, by 

 the fusion of the mineral idocrase. Von Kobell, in 1827, fused the 

 natural melanite garnet and allowed it to cool gradually when it 

 assumed the octahedral form which is rarely seen in nature. 



A survey of the whole work of mineral synthesis shows that 

 previous to 1849, twenty-three minerals had been formed in the labo- 

 ratory, while since that year over one hundred others have been 

 reproduced. The year 1850 marks the real beginning of this impor- 

 tant work. The number of minerals not artificially formed is quite 

 small. Foque and Levy in their work on this subject published in 

 1882, noted thirty minerals as not reproduced and described the 

 formation of one hundred and thirty species thus leaving a number of 

 less important minerals without mention. 



Zirkel, in his new petrography published near the end of 1893, 

 gives a list of seven minerals not >et reproduced. These are epidote, 

 allanite, zoisite, staurolite, disthene, aiidalusite, and tourmaline . It is 

 interesting to note that with one exception (allanite) these are meta- 

 morphic minerals, showing that the exact conditions of metamorphic 

 action have not yet been realized in the laboratory. 



IV. ROCK SYNTHESIS* 



When the artificial reproduction of the important minerals was 

 accomplished, the attempt was made to unite these into rocks like 

 those occurring in nature. Foque and Michel Levy were the 

 pioneers in the work, commencing their work in 1877 and achieving 

 great success in a short time. In the following five years they 

 reproduced nearly all the basic rocks and'made important discoveries 

 concerning the origin of the acid series. 



* See plate IV, taken from Foque and Levy's work, which represents thin 

 sections of artificial leucite tephrite and artificial basalt magnified. 



