THE AMERICAN MUSEUM JOURNAL 



idea of the enormous size attained by the early Pleistocene or 

 preglacial elephants of this country. 



A POSSIBLE AMERICAN KIMBERLEY. 



A SERIES of interesting specimens have been received in the 

 Department of Mineralogy from the Kentucky Diamond Mining 

 and Developing Company, which are related to the efforts about 

 to be made by this company in their search for diamonds in 

 Elliott County, eastern Kentucky. 



The specimens consist of a large nodule of a green rock 

 known to Hthologists as dunite, and composed of chrysolite 

 ■ {peridot) and pyroxene (eiistatite) with garnet and an iron 

 mineral (ilmenite), with a few specks of mica, the whole greatly 

 changed and converted through most of its mineral texture into 

 serpentine. With this dense rock, taken below the surface, are 

 specimens of the pulverulent, friable and weathered surface rock. 

 This surface rock in weathering discharges the more resistant 

 grains, crystals and fragments of iron oxide and garnet which 

 collect in the stream beds of the region. 



A number of specimens, also, of semi-graphitic or coaly 

 character, accompany the peridotitic lumps and nodules which 

 have been taken from beds traversed by the former, where it 

 exists as an eruptive dike rising above the adjacent country. 



The speculative basis which is afforded by the presence of 

 this rock in Kentucky is its association with carbon-bearing 

 strata, carboniferous sandstones and shales. It is surmised, 

 after analogies drawn from the diamond region of South Africa, 

 where a similar association seems established, that as the i)livine 

 rock in Kentucky is plainly an eruptive rock, in its passage up- 

 ward through these carbonaceous deposits carbon vapors may 

 have been formed, and their absorption by the liquid magma of 

 the exuding rock resulted in the formation of diamonds. 



The "necks" of volcanic rock at Kimberley, S. A., perforate 

 adjacent carbonaceous shales, and the origin of the diamond in 

 that locality has been attributed to their tliermal and static 

 action upon carbon vapors, disengaged from tliese strata. 



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