820 MINERALS YEARBOOK, 1967 
 
total commercial value. While less than one-tenth of the sand output was
marketed as special industrial silica sands used for glass manufacture, engine
sand, filler, and other nonconstruction uses, about twotenths of the value
of sand output was attributed to these market uses. 
 Eighty-nine percent of the total commercial sand and gravel output was screened,
washed, or otherwise processed compared with 83 percent in 1966. Of the 78
commercial sand and gravel operations reporting, 55 processed their output
at 41 stationary, 11 portable, and 3 dredging installations. The remaining
23 operations recovered unprocessed material. Of the commercial tonnage,
60 percent was shipped by truck, and most of the remainder by rail or water;
a small quantity was used at the processing plant or transported by unspecified
methods. 
 Production of sand and gravel was reported from 36 counties and 2 independent
cities, compared with 30 counties and 3 independent cities in 1966. In order
of output the principal sand-and-gravel producing areas were Henrico, Fairfax,
and Chesterfield Counties, the independent city of Virginia Beach, and Prince
George County. Almost three-quarters of both the total output and value were
contributed by these five producing areas. 
 Of the 78 commercial sand and gravel operations reporting in 1967 (60 in
1966), 3 had an output range of from 500,000 to 
1 million tons and accounted for 26 percent of the total commercial output;
21 had an output range of from 100,000 to 500,000 tons and accounted for
54 percent; 19 had an output range of from 50,000 to 100,000 tons and accounted
for 13 percent; and 35 had an output range of up to 50,000 tons and accounted
for 7 percent. The number of operations producing less than 50,000 tons of
sand and gravel annually was over double that of 1966. The bulk of sand and
gravel recovery was by dredging and open pit mining; a sizable tonnage of
industrial silica sand was produced from crushed sandstone and quartzite
and a limited quantity was obtained in the beneficiation of kyanite ore.

 
 Soapstone.—Crushed and ground soapstone was produced by Blue Ridge
Talc Co., Inc., near Henry, principally for use in insecticides and foundry
facings. Output 
and value were moderately less than in 1966. Soapstone used as a dimension
stone is included with miscellaneous stone in the stone section of this chapter.

 
 Stone.—Stone, after coal the most important mineral commodity produced
in Virginia, accounted for 18.5 percent of the State's total value of mineral
production in 1967 (20.3 percent in 1966). Compared with 1966, production
and value declined 8 percent and 6 percent, respectively. A lessened demand
for construction aggregates (concrete aggregate and roadstone) was mainly
responsible for the decline in production and value. A lower output of limestone
derived products, in addition to aggregates, was also contributory. 
 Varied types of stone were mined or quarried in the State; in order of output
value they were limestone (including dolomite), granite, basalt (including
diabase), slate, miscellaneous stone (including amphibolite, schist, soapstone,
and "Virginia Greenstone"), sandstone (including quartzite and quartz), calcareous
marl, and marble. Both crushed or ' broken stone and dimension stone were
produced. Marine shell (oystershell) was also produced, chiefly by dredging
reef shell deposits in Chesapeake Bay; a limited quantity was obtained as
a coproduct of oyster processing. 
 Crushed stone comprised virtually all of the total output (99.8 percent)
and the major share of the total value (91.2 percent). Crushed stone was
produced from all the stone varieties, although that prepared from limestone,
granite, and basalt, the three leading stone varieties in order of output
and value, accounted for 94 percent of total stone output and 86 percent
of total value. Of the total crushed stone output, 22.9 million tons, or
73 percent, was used for building purposes (concrete aggregate and roadstone)
compared with 24.6 million tons in 1966. In addition 11 percent was limestone
used in cement and lime manufacture; 3 percent was used as fluxstone (limestone);
and the remainder was used as agricultural dressing, railroad ballast, riprap,
stone sand, and in miscellaneous and unspecified applications. 
 Of the three leading crushed stone varieties only basalt (including diabase)
gained in output (28 percent) and value (27 percent). Granite declined 13
percent