215The Mineral Industry 
of Connecticut 
This chapter has been prepared under a cooperative agreement between the
Bureau of Mines, U.S. Department of the Interior, and the Connecticut Geological
and Natural Historical Survey for collecting information on all minerals
except fuels. 
 
 
By Curtis D. Edgerton1 
 
 
 Value of mineral production in Connecticut declined 3 percent from that
of 1966. Most of the decrease was attributed to lower sales in the stone,
sand and gravel, and lime industries although small decreases in sales also
occurred in the feldspar and mica industries. The mineral commodity which
produced the greatest revenue was stone, followed closely by sand and gravel.
Sales of these commodities declined about 3 percent each, largely owing to
a lessening in construction activity. 
 H~rtford County led, the State in value of minerals produced, followed by
New Haven, Litchfield, Middlesex, New London, Windham, and Fairfield Counties.
Operations in Tolland County produced relatively small quantities of sand
and gravel. 
 The Federal Geological Survey published bedrock geological maps of the Uncasville,
New London, Columbia, Montville, Niantic, Watch Hill, and Springfield 
South Quadrangles. In addition, the Survey published a surficial geologic
map of the Roxbury Quadrangle, and issued a Hydrologic Investigations Atlas
of the Connecticut River Basin. Nine reprints of topographic maps were issued
by the Survey, and the Naugatuck Quadrangle was revised. The Federal Survey,
in cooperation with the Connecticut Geological and Natural History Survey,
published a report entitled "The Engineering Geology of the Northeast Corridor,
Washington, D.C., to Boston, Mass." The Connecticut Survey published Quadrangle
Reports on the bedrock geology of the Old Lyme Quadrangle, and the bedrock
geology of the Waterbury Quadrangle. The Survey also issued a report on the
surficial geology of the Hartford South Quadrangle, and one on the stratigraphy
and structure of the western part of the New Haven Quadrangle. 
 
1 Geologist, Bureau of Mines, Pittsburgh, Pa. 
 
Table l.—Mineral production in 
Conne 
cticut1 
 
 
Mineral 
 
1966 
 
1967 
 
Quan- 
tity 
Value 
(thousands) 
Quan- 
tity 
 Value — (thousands) 
Clays ,thousand short tons -Gem stones                                  
    Sand and gravel thousand short tons -Stone ~ 
Value of items that cannot be disclosed: 
Feldspar, lime, mica (scrap), and peat (1966)            
 
Total                       
- Total 1957—59 constant dollars                     
192 NA 
9,561 
5,618 
 
XX 
$296 
8 
8,963 
10,482 
 
1,597 
191 NA 
8,320 
5,097 
 
XX 
$334 
8 
8,710 
10,141 
 
1,426 
 
XX 
XX 
21,346 
20,652 
XX 
XX 
20,619 
P20,056 
 Preliminary. NA Not available. XX Not applicable. 
 ' Production as measured by mine shipments, sales, or marketable production
(including consumption by producers).