PETROGRAPHIC CHARACTER OF OHIO SANDS 159 
Corundum.—Corundum is occasionally found in sands of all ages. 
Magnetite——More or less magnetite is always present. It is found both 
as free grains and inclusions in other minerals. In the glacial drift sands it is 
a prominent constituent. 
Ilmenite and leucoxene.—I|menite is sometimes mixed with magnetite. — Its 
presence is shown by leucoxene, an alteration product. 
Titanite.—Titanite is occasionally seen in the recent sands of glacial drift 
origin. 
Monazite—Monazite is sparingly distributed in very small amounts in 
Ohio sands. It was noticed in three recent sands and seven sandstones. 
Xenotime.—Xenotime is occasionally found in small amounts in sandstones 
near the base of the Coal Measures and in residual sands derived from these. 
It was noticed in twenty-two rock samples most of which were taken from the 
Sharon Conglomerate. 
Hematite—Hematite is quite common as inclusions in quartz. Earthy 
red hematite is sometimes a cementing material in sandstones. 
Limonite—Limonite is always present. It is a common cementing 
material in sandstones. In most of the sandstones examined the limonite 
content is less than 2 per cent. The grains of residual sands are usually thickly 
coated with limonite. 
Kaolinite—Kaolinite is a prominent constituent of most sands. In feld- 
spathic sandstones it may constitute several per cent of the make-up. 
Chlorite, serpentine, epidote—These are of common occurrence in the Car- 
boniferous sandstones. They are largely responsible for the greenish and 
bluish colors so often seen in those rocks. 
Calcite and dolomite—These were found as cementing material in the 
Sylvania sandstone of northwestern Ohio. Slight amounts, probably com- 
minuted limestone, are sometimes seen in the glacial drift sands. 
Pyrite—No pyrite was seen in the sand samples but small limonite 
stained cavities probably due to oxidation of pyrite were seen in one sandstone. 
It is common in the deeper workings of quarries. 
One of the interesting features brought out by the investigation 
is the entire absence of garnet in the old sandstones of Ohio. 
Inquiry and personal search show that this is not a local condi- 
tion but that the scarcity or absence of garnet in the older sand- 
stones is prevalent in widely separated regions. The West Virginia 
Geological Survey has recently made a petrographic examination 
of about thirty sandstones and garnet was found in only one 
of these—a sample from the Dunkard series.*. Dr. A. A. Julien, 
whose study of sands has been very extensive, writes: “The 
1G. P. Grimsley, ‘‘Iron Ores, Salt and Sandstone” West Virginia Geol. Surv., 
IV (1909), 447. 
