PIKE COUNTY. 
151 
is thoroughly soaked with water, it is brittle and breaks with a 
splintery conchoidal fracture. When dry and rubbed with the hand 
it takes on a satin-like gloss. Ground to a fine powder and wet, it 
forms a nonplastic or but partially plastic mass. 
A sample of this kaolin that had been left to air dry for several 
months and then submerged in water cracked to small angular pieces 
with plainly audible snapping sounds, very much as if it had been a 
piece of hot glass. Within five minutes the breaking had ceased, and 
though the kaolin remained in water for several days, it showed no 
further signs of being affected by it. 
The fact that this kaolin does not soften in water like clay is a dis- 
advantage, for it would need to be ground and washed before it could 
be used in the manufacture of fine pottery. A sample of it has been 
put to a practical test by being fired and glazed in one of the New 
Jersey potteries. It stood this test in a very satisfactory manner. 
Below are given analyses of both the upper pink and the lower 
white kaolin of the section given on page 149. The locality is in the 
NW. J SW. 1 sec, 19, T. 8 S., R. 24 W. These analyses may be com- 
pared with those of well-known kaolins in the table on pages 236-237. 
Analyses of kaolins from, Vaughn Creek. 
[Dr. T. C. Van Nuys, analyst.] 
Upper 
bed. 
Lower 
bed. 
Silica (Si0 2 ) 
48.87 
36.51 
.98 
.19 
.25 
47.39 
Alumina (AI2O3) 
34. 67 
Iron (ferric) oxide (Fe20 3 ) 
2.31 
Lime (CaO) 
.32 
Magnesia (MgO) 
Trace. 
Potash (K 2 0) 
.20 
Soda (Na 2 0) 
.39 
Water 
13.29 
13. 89 
Water at 110°-115° C 
100. 11 
97.17 
1.00 
At the pit from which the sample of the lower bed was taken the 
kaolin is much fractured, and iron-charged waters have infiltrated 
along these fracture lines and stained them a deep brown color, 
though the material still holds together compactly. When a mass 
removed from the bed is struck hard, it breaks along these fractures. 
The iron stain seriously injures the kaolin, probably rendering it 
worthless for fine ware. It is evident, however, that the iron lias 
been leached from the waterworn gravels, sands, and clays that cover 
the surface of the ground and has been redeposited in the only part of 
the kaolin it could easily penetrate — that is, along these crevices. If, 
therefore, kaolin available for the manufacture of the finer grades of 
porcelain exists in commercial quantities in the neighborhood of the 
Vaughn Creek pits, it should be looked for at places where it will have 
a covering thick enough to protect it from infiltration of iron-charged 
waters from the surface. 
