THE MINERAL INDUSTRY OF NEW JERSEY 
545 
 
 Perlite.—Crude perlite mined in Western States was expanded at three
plants, one each in Mercer, Middlesex, and Somerset Counties. The Hillside,
Union County plant of Certified Industrial Products, Inc., discontinued operations.
Output of expanded perlite was reported for the first time from the Trenton,
Mercer County, plant of Zonolite Division, W. R. Grace & Co. The Burlington
plant of National Gypsum Co. used expanded perlite produced at its Baltimore,
Md., plant. Although total State shipments and value dropped below the levels
of 1966, totaling 6,000 tons valued at $381,000, the average unit values
were greater. Expanded perlite was used primarily in acoustical plaster;
other uses included concrete aggregate, loose-fill insulation, soil conditioner,
and as filler material. 
 
 Pigments.—Metal-base pigments, used primarily for manufacturing paint,
were produced at several New Jersey plants. Iron oxide pigments were produced
by E. I. du Pont de Nemours & Co., Newark; Columbian Carbon Co., Trenton
and Monmouth Junction; and Stabilized Pigments, Inc., Edison. Titanium dioxide
was produced by The New Jersey Zinc Co., Gloucester City, and National Lead
Co., Perth Ambo~r. National Lead Co. also manufactured lead pigments at Perth
Amboy. Zinc oxide and leaded zinc oxide pigments were produced by Royce Chemical
Co., Canton Hill. 
 
 Sand and Gravel.—A continuing high level of highway and building construction
resulted in greater production of sand and gravel. Output increased 5 percent,
but value rose only 2 percent due primarily to less production of higher
priced ground sand. Average unit values for construction sand and gravel
remained relatively stable. Although almost all of the production was by
commercial operators, limited quantities were produced by Government-and-contractor
operations in Atlantic County. Over 13.1 million tons of the commercial output
was used in construction as building and paving material compared with 12.4
million tons in 1966. Most of the industrial sand production was for the
foundry and glass industry markets. Ground sand production decreased 17 percent,
but Unground industrial sand output increased. 
Ground sand was produced in Cumberland, Middlesex, and Ocean Counties. 
 Sand and gravel was produced in 14 of the State's 21 counties. Morris County
led in tonnage, but Cumberland ranked first in value because of higher priced
industrial sands. Other important areas with production exceeding 1 million
tons were Bergen, Burlington, Camden, Middlesex, and Ocean Counties. Of the
109 commercial operations (104 in 1966) only one had production exceeding
900,000 tons. Eight operators produced between 500,000 tons and 900,000 tons.
The majority of producers had tonnages ranging from 25,000 tons to 300,000
tons, with only 18 operators producing below 25,000 tons. Commercial producers
processed 16.2 million tons of sand and gravel by washing, crushing, sizing,
or screening. Shipments to consumers were primarily by truck (15.4 million
tons) and rail (2.5 million tons). 
 In National Sand and Gravel Safety Competition, Houdaille Construction Materials,
Inc. was awarded Certificates of Achievement in Safety for its Kenvil, Riverdale,
and Lakewood plants for working without any lost-time injuries. 
 
 Stone.—A continuing high level of highway construction in the State's
northern and western counties created a steady demand for stone aggregates.
An increase in total stone production of 1 percent was attributed primarily
to the opening of additional granite quarries in Sussex and Hunterdon Counties.
Stone production was reported in 11 counties, led by Somerset, Passaic, Sussex,
and Hudson Counties, in decreasing order of value. Types of stone produced
included basalt, granite, limestone, marble, oystershell, sandstone, and
miscellaneous stone. Basalt (traprock) continued as the leading type of stone
quarried, and accounted for 84 and 80 percent respectively, of the State's
total production and value. Output was 1 percent below the level of 1966;
average value decreased from $2.13 per ton to $2.12. Somerset County with
5.4 million tons and Passaic County with 2.3 million tons were the leading
basalt-producing areas. Quarries were also active in Essex, Hudson, Hunterdon,
Mercer, and Union Counties. Eightyeight percent of the output was used as