PRECIOUS STONES 325 



1890 a few othors have been found in these regions, and some 

 in the northwestern states, varying from one third of a carat 

 to 21 carats in weight. 



The northwestern diamonds are very interesting as being 

 contained in the deposits of the glacial drift, scattered along an 

 irregular line of some 600 miles, from Wisconsin to the vicinity 

 of Cincinnati, Ohio. All the material distributed b}^ this 

 ancient glacial action has been brought down from the north, 

 and therefore the source of these diamonds is somewhere in the 

 unexplored regions of Canada and not in the United States. 

 Geologists recognize two distinct drift deposits in the western 

 states, called the older or Illinoian drift, and the later or Wis- 

 consin drift. Some of the diamonds found in Indiana and in 

 Wisconsin are referred to one of these drifts and some to the 

 other, though most of them belong to the later. The whole 

 num]:)er of diamonds actually known from these glacial deposits 

 amount to about 25, over half of which are from Wisconsin and 

 one third from Indiana. 



The localities of discovery during the period since 1890 are 

 as follows: 



Alabama. — Shelby county, one of 4^ carats. Lee county, 

 one of 3 carats. 



California. — A number of localities, chiefly in the central 

 portion of the state, in connection with the hydraulic gold 

 washings of Amador, Butte, Eldorado, and Nevada counties. 

 A single diamond is reported from Tulare count}^, and a number 

 of very small ones in the gold sands of streams in Del Norte and 

 Trinity counties. No large stones have been found in Cal- 

 ifornia, and nowhere are they abundant enough to lead to any 

 mining for them. Nevertheless some handsome ones have been 

 casually obtained in the central counties above named, chiefly 

 in the ancient gold-bearing gravels overlaid by lava flows, and 

 fragments of diamonds crushed by the stamp mills are not un- 

 common in the flumes and sluices. Most of the stones found 

 wathm recent years have come from the vicinity of Placerville, 

 Eldorado count3^ 



Indiana. — Brown county, five — one of 2 carats, others 

 very small. Morgan county, three — one of 3 J carats, others 

 very small. 



