ABRASIVE MATERIALS 661


 The commercial production in the United States of pebbles used for grinding
minerals, ores, cement, and for other purposes, together with the output
of quartzite blocks for tube-mill liners, includes, so far as is known to
the Bureau of Mines, only the output of beach pebbles in southern California
and of cut cubes and cut liners of quartzite in Minnesota. The figures in
the following table appear, to cover the entire commercial output, but doubtless
additional production for local use or use by companies other than those
reporting was unrecorded.
 The following table contains production data for the past 5 years:

Pebbles for grinding and flint lining for tube mills sold or used by producers
in. the
United States, 19~d8—32
Year
Short tons
Value
Year
Short tons
Value
1928                 
6,288
$89,321
1931                  
2,024
$26,211
1929                 
4,630
66,178
1932                
976
13,070
1930                 
3,480
50,816




GARNET AND EMERY

 Garnet.—In 1932 the production of garnet decreased 62 percent from
the 4-year average for 1928—3 1, compared with a decline of 51 percent
in shipments of abrasive paper and cloth during the same period.
 The bulk of the domestic garnet production is used by the abrasive paper
and cloth industries. Garnet* constituted 39 percent of the abrasives used
in the manufacture of these products in 1919 but only 23 percent in 1930,
whereas the quantity of artificial abradants so used increased from 20 to
46 percent. Some garnet is used for grinding plate glass where competition
with emery and various grades of grinding and polishing sand exists.
 According to price quotations the price of garnet has changed little during
the last 3 years. Nevertheless, the average value of the mineral per ton,
as reported to the Bureau of Mines for 1932, increased almost 15 percent
from 1931, owing, no doubt, to the fact that a greater part of the sales
were of higher-grade material.
 New York, producing a quality of mineral recognized as standard, holds chief
place in the output of abrasive garnet. New Hampshire ranks second. Other
States in which deposits of past or future commercial importance are known
to exist are Connecticut, Pennsylvania, North Carolina, Georgia, Virginia,
Colorado, California, Idaho, Montana, Nevada, Arizona, Utah, and other Western
States.
 Total production of garnet for the past 5 years is listed in the following
table:

Abrasive garnet sold or used by producers in the United States, 19~8—32
Year
Short tons
Value
Year
Short tons
Value
1928                 
6,617

5,961

5,003
$459, 307

435,420

314,129
1931                
2,946

1,950
$193, 015

147,350
1929                 
1930                 


1932