A PRELIMINARY REPORT ON CLAYS OE ELORIDA 
127 . 
clays are common along the Apalachicola River, one such deposit being 
worked by the Guilford Brothers Brick Company at Blountstown. 
The Guilford Bros, plant is situated about one-half mile south of 
Blountstown on a spur of the Marianna and Blountstown Railroad and 
about one-half mile from a barge landing on the Apalachicola River. 
Thus both rail and water shipping facilities are afforded. 
The deposit is overlain by soil averaging about six inches in thick¬ 
ness and is underlain in places by sand. The deposit is somewhat lentic¬ 
ular, but averages from four to nine feet in thickness. The clay is dug 
away from the pit face, then heaped up and allowed to weather for an in¬ 
definite time. Sand and mica are present in this clay to a slight extent. 
The clay is at present being used for the manufacture of common 
brick and at the time the field work was being carried on, brick from this 
plant was being used in the construction of the Post Office Building at 
Apalachicola. This clay may be used for face or common brick, drain 
tile, hollow blocks, flower pots, turpentine cups, ballast, etc. It has the 
following properties: 
Physical Properties of Guilford Bros. Brick Company Clay (Lab. No. o-6). 
Excellent. 
Plasticity, judged by feel. . . . 
Water of plasticity. 
Pore water. 
Shrinkage water. 
Linear air shrinkage. 
Volume air shrinkage. 
Modulus of rupture, average 
Slaking test. 
Steel hard at cone 1. 
Overfires at cone 16. 
Fire tests: 
29.75% 
0.93% 
28.82% 
9.7 % 
32.20% 
421.7 pounds per square inch. 
30 hours. 
Temperature. 
Linear Shr. 
Per Cent. 
Absorption. 
Per Cent. 
Porosity. 
Per Cent. 
Color. 
950°C. 
0.3 
17.10 
34.00 
Brick red. 
1050 
0.3 
18.20 
34.60 
Brick red. 
1150 
7.3 
11.30 
26.20 
Brick red. 
1190 
7.3 
6.50 
18.50 
Brick red. 
1230 
7.3 
6.35 
16.80 
Brick red. 
1310 
7.8 
4.23 
16.40 
Chocolate. 
1370 
7.8 
3.42 
13.10 
Chocolate. 
1430 
7.8 
3.82 
14.40 
Chocolate. 
