THE MINING AND QUARRY INDUSTRY I9IO 29 



pressure as when used on polishing machines. Another factor that 

 has a bearing upon the value of abrasive garnet is the size of the 

 product which can be secured in the ordinary practice of mining 

 and separation. If the crystals are small or have been badly shat- 

 tered or granulated by compression after crystallization the product 

 may be too fine in the average to yield the necessary assortment 

 of sizes. It is an advantage, rather than otherwise, however, that 

 the garnet should possess an imperfect cleavage, so that on crushing 

 the grains show one or more smooth surfaces. These surfaces 

 permit firm attachment to the cloth or paper and also provide a 

 sharp cutting edge. Color is no criterion of quality in ordinary 

 garnet, but abrasive users seem to prefer the darker shades of red 

 which approach the distinctive garnet color. 



In the last few years Spanish' garnet has been sold in the Ameri- 

 can market in competition with the domestic product. The garnet 

 is said to be obtained from alluvial sands. It is produced at a lower 

 cost than the Adirondack garnet and pays no import duty. It comes 

 only in the finer sizes so that its use is somewhat limited. The 

 imports in 191 o amounted to about 775 short tons with an invoiced 

 value of $14,830. The imports in 1909 were 536 tons valued at 

 $10,315. The principal ports of entry are New York, Boston and 

 Chicago and the shipments are generally made through English 

 ports. 



GRAPHITE 



An output of 2,619,000 pounds of crystalline graphite was re- 

 ported last year from the Adirondack region. This was a substan- 

 tial gain over the total of 2,342,000 pounds reported for 1909, but 

 represented only an average output for the industry which has been 

 subject to rather extensive fluctuations. The maximum product for 

 any one year was in 1905 when it amounted to 3,897,616 pounds ; a 

 sharp decline during the next few vears brought the total down to 

 1,932,000 pounds in 1908, since which time the industry has partly 

 recovered its place. 



The Adirondack graphite continues to find a good market. The 

 returns from the mining companies show for last year's product 

 a value of $160,700, or slightly more than 6 cents a pound. This 

 does not represent the actual selling price, but rather a base or 

 average for the mine output which is marketed under many differ- 

 ent grades of widely varying value. 



There have been few new features in the industry during the last 

 year or two. In fact less interest has been manifest in exploration 



