DIAMOND FIELD OF THE GREAT LAKES 379 



escaped identification, hardly admits of reasonable doubt, when 

 it is borne in mind that three of the stones found (including the 

 two of largest size) remained in the hands of the farming popu- 

 lation without their nature being discovered, for periods of eight 

 and one half, seven, and over fifteen years, respectively. If it 

 were possible to visit all the homes in the lake region, I have no 

 doubt that many diamonds would be discovered in the little col- 

 lections of pebbles and local "curios" which accumulate on the 

 clock shelves of country farmhouses. 



Since 1894, when the writer published a note on the Eagle, 

 Oregon, and Kohlsville diamonds, and ventured to predict that 

 other diamonds would occasionally be found in the glacial drift, 

 they have been coming to light in this region, at the rate of 

 about one each year, though not apparently as the result of 

 search in any case. 



PHYSICAL CHARACTERISTICS OF THE LAKE DIAMONDS 



It will be profitable to consider the physical peculiarities of 

 the several diamonds which have been found in the lake region, 

 and to compare them with one another in order to determine 

 whether points of resemblance or of difference are the more 

 remarkable. They may be considered in respect to size, form, 

 surface, and color. The observations of specific gravity and of 

 index of refraction, which would be of great interest, have not 

 as yet been carried out upon them. 



Size. — The size of the lake diamonds is best indicated by 

 their weights, which range from 2\\ carats (Kohlsville) to the 

 microscopic diamonds of Plum Creek. In descending order the 

 weights of the stones which have been examined are respectively 

 2i|, 15J-I, iof, 6if, 6, 3ff, 2 T V 2, f|, T V, and ^ carats. While 

 the average weight of these is over 6 carats, it cannot be con- 

 sidered an average for the region, since only the larger stones 

 are likely to be discovered until a systematic search is under- 

 taken in the region. At Plum Creek, where panning of the 

 gravels was undertaken, the diamonds found were mostly small, 

 the largest beinaf of 2 carats weigfht. 



