PETROGRAPHIC CHARACTER OF OHIO SANDS 157 
results of weathering. Many minerals present in the sandstones 
have been eliminated and there remains little besides the quartz, 
which is itself usually heavily coated with limonite. The glacial — 
drift sand is a hodgepodge mixture of anything that happened 
to be in the path of the ice. Travel-rounded grains derived from 
sand deposits are mixed with sharp particles produced by the com- 
minution of rock. Minerals of an unstable nature recently derived 
from the crystalline rocks are abundant and these show little 
alteration. 
MINERAL SUMMARY 
Thirty-four minerals have been recognized in Ohio sands. Some 
of these are abundant in practically every sample while others are 
less widely distributed and are only present in small amounts. 
While the samples were taken from all parts of the state from sands 
of all ages they can hardly be regarded as representative of many 
of the formations because only those outcrops which appeared 
suitable for glass or molding were sampled. A list of the minerals 
is given with notes as to the occurrence of each. 
MINERALS OF OHIO SANDS 
Quartz Garnet 
Orthoclase Corundum 
Plagioclase Magnetite 
Microcline Ilmenite 
Hornblende Leucoxene 
Actinolite Titanite 
Diopside Monazite 
Augite Xenotime 
Enstatite Hematite 
Hypersthene Limonite 
Muscovite Kaolinite 
Sericite Chlorite 
Tourmaline Serpentine 
Zircon Epidote 
Apatite Calcite 
Rutile Dolomite 
Biotite Pyrite 
Quariz.—Quartz is by far the most abundant mineral in all sands examined. 
It usually constitutes over 90 per cent of the make-up of the old sandstones. 
Only twelve out of ninety-one samples examined contained less than 90 per 
