A PRELIMINARY REPORT ON CLAYS OF FLORIDA 
1(31 
Physical Properties of State Hospital Red Sandy Clay (Lah. No. 0 - 37 ). 
Plasticity, judged by feel. 
Water of plasticity. 
Pore water.. 
Shrinkage water .. 
Linear air shrinkage. 
Volume air shrinkage. 
Modulus of rupture, average. 
Slaking test. 
Fire tests: 
Fair. 
21.40% 
0 . 10 % 
21.30% 
6.40% 
17.90% 
84.5 pounds per square inch. 
36 hours. 
Porosity. Color. 
Per Cent. 
36.70 Brick red. 
36.50 
36.50 
Temperature. Linear Shr. Absorption. 
Per Cent. Per Cent. 
950°C. 0.6 22.37 
1050 0.6 18.40 
1150 1.4 17.45 
A surface clay exposed on the A. J. Key Plantation, about three 
miles southeast of Quincy on the Seaboard Air Line Railway, contained 
numerous limonitic concretions. The plasticity and drying qualities are 
good, but the transverse strength is very low. This clay is of no practical 
value for the manufacture of burned products. Its physical properties 
are: 
Physical Properties of Key Plantation Clay (Lab. No. 0 - 4 . 1 ). 
Plasticity, judged by feel.... 
Water of plasticity. 
Pore water. 
Shrinkage water. 
Linear air shrinkage. 
Volume air shrinkage. 
Modulus of rupture, average 
Slaking test. 
Overfires at cone 5. 
Excellent. 
24.75% 
0.27% 
24.48% 
5.70% 
15.75% 
92.5 pounds per square inch. 
24 hours. 
Fire tests: 
\perature. 
Linear Shr. 
Per Cent. 
Absorption. 
Per Cent. 
Porosity . 
Per Cent. 
Color. 
950°C. 
0.3 
26.60 
45.80 
Brick red. 
1050 
0.8 
24.48 
43.10 
Brick red. 
1150 
2.3 
23.55 
43.60 
Brick red. 
1190 
3.3 
16.70 
37.10 
Brick red. 
By far the best clays in the county for burned products are the 
flood-plain clays along the Apalachicola and Ocklocknee rivers. One 
such deposit is located on the State Hospital Farm, about one mile north¬ 
west of Chattahoochee, in a field joining the Apalachicola River and the 
Georgia-Florida boundary. The thickness of this deposit is not definitely 
known, but it is more than five or six feet. It is known to underlie an 
area of sixty or eighty acres in Georgia and Florida. 
