Ohio Geology and Collecting locations

  Only Paleozoic rock formations underlie  Ohio’s Pleistocene surface debris and Quaternary soils.  For long ages Ohio lay beneath a shallow sea which received successively enormous quantities of Ordovician, Silurian, Devonian, Mississippian and Pennsylvanian sediments; the erosional products of some 200  million years.  Few, if any Mesozoic rocks appear within the state, but every one of Oh io’s 88 counties is surfaced with Pleistocene debris.  The state was buried completely four  times by Ice Age glaciers, leaving the land
surface nearly level but with some fairly rugge d low hills in the southeastern corner.  There are few localities containing worthwhile gems or minerals, although excavations in the underlying black, Upper Devonian (New Albany) shales occasionally produces pieces of silicified wood.

  Ohio ranks first in the nation in the  production of limestone and dolomite, and second in the production of clays.  Lesser prod uction of iron, petroleum, natural gas and coal from thick beds contributes to the mineral econom y.  But as far as the collector is concerned, Ohio is unique in but a single gemstone, an exceptionally high quality, colorful flint that is mostly a mixture of chert, translucent chalcedony, jasp-agate and common opal, rivaling in beauty the Arizona agatized wood.  This gem flint occurs in the 8 mile long Flint Ridge, between Newark (Licking Co.) and Zanesville  (Muskingum Co.), a region of rolling, wooded hills.  Here, prehistoric Indians quarried the toolmaking material for arrowheads and other implements.

  While occurrences are widespread throughout  Ohio, the chief deposits of true flint (characterized by ease of working) include the highly colored  Vanport   flint of the Flint Ridge and the Upper Mercer  flint exposed in Hocking, Perry, and Coshocton counties.  Early American settlers also quarried a rough, porous flintstone from outcrops, especially around McArthur, Vinton Co., for making the burstones  they needed for grinding grain in their water mills.

  Other collectable minerals are rare, alth ough quarries in the western counties, especially the Clay Center Quarry 12 miles sout heast of Toledo but in Ottawa Co. between Rtes. 51 and 579 yield good specimens of  Celestite,  Dolomite crystals,  Fluorite (fluorescent),  ,  Galena,  Marcasite,  Pyrite,  Selenite and  Sphalerite.  A few alluvial Diamonds have been found.

ASHTABULA COUNTY
  CONNEAUT, area pits, quarries, rd. cuts, etc. ⎯cone-in-cone  Calcite.

CLERMONT COUNTY
  MILFORD, area creek gravels and alluvial deposits, rare ⎯Diamond.

CLINTON COUNTY
  WILMINGTON, area of Todd’ s Ford, a mineral deposit ⎯Hematite.

COSHOCTON COUNTY
  AREA, townships of Washington, Virginia, Bedford, Jackson, Jefferson, Bethlehem, Monroe and Clark; on regional knobs and ridges and just above areas of drainage in A Location Guide for Rock Hounds in the Untied States 337 townships of Franklin, Keene, Mill Creek and Tuscarawas, as hard dark gray to black nodules⎯flint.

CUYAHOGA COUNTY
  CHAGRIN FALLS (on Geauga Co. line), area quarries ⎯oilstone.

DELAWARE COUNTY
  DELAWARE, area Co. exposures of bl ue clay, as clusters and nodules⎯Pyrite (crystals sharply cubic).

FRANKLIN COUNTY
  COLUMBUS, area countywide exposures of  blue clay in rd. cuts, pits, quarries, excavations⎯Pyrite (clustered crystals sharply cubic).

HIGHLAND COUNTY
  SINKING SPRING, area ore deposit (most important in Ohio)  ⎯Hematite.

HOCKING COUNTY
  AREA exposures throughout Co. of the U pper Mercer horizon, commonly represented by black flint of excellent quality:  c  Benton Twp. Map, Sec. 24,  along high ridges and knobs, as nodules⎯flint;   d  Green Twp., 2½ mi. SW of Kachelmacher and 1 mi. W of Freeland School⎯flint; (high quality);   e  Sec. 23, E center, in a hollow as scattered nodules ⎯flint;   Washington Twp., SW part of Sec. 31 in a gully on the knob⎯flint.

HOLMES COUNTY
  AREA, townships of Berlin, Hardy, Killbuc k, Mechanic, Paint and Salt Creek (with occurrences in shale or sandstone); and conspicuous deposits in townships of Clark (limestone occurrences), Prairie and Walnut Creek ⎯flint.

JACKSON COUNTY
  AREA, townships of Bloomfield, Coal, Hamilton, Jefferson, Franklin, Lick, Madison and Milton, as nodules in the Vanport member ⎯flint.

LAWRENCE COUNTY
  AREA, townships of Decatur, Elizabeth, Pe rry, Symmes, Upper and Washington, as nodules in limestone exposures⎯flint.

LICKING & MUSKINGUM COUNTIES
  AREA, from 3 mi. SE of Newark, Lick ing Co., to 12 mi. NW of Zanesville, Muskingum Co., 8 mi. long by ¼ mi. wide:  c  Flint Ridge ⎯agate ,  Amethyst ,  carnelian , chalcedony ,  chert  (various colors), jasper-like  flint,  jasp-agate,  jasper,  Smoky Quartz Ohio 338 crystals, clear  Quartz.  From Brownsville, Licking Co., take US 40 E 3 mi., turn N to Flint Ridge State Park, and area of 10 mi. radius of private lands⎯gem flint.   d  Regional rd. cuts, banks, stream banks and beds⎯gem flint, translucent  chalcedony, drusy quartz .

LUCAS COUNTY
  SYLVANIA, SW, at jct. of Brint St. and Ce ntennial rd., the Medusa Quarry (SW of 4 quarries), very many specimens⎯fossils (some replaced by Marcasite), hollow shells lined with Calcite crystals or Marcasite.
  WHITEHOUSE, area quarries ⎯Celestite,  Gypsum.

MUSKINGUM COUNTY
 AREA⎯agate ,  Amethyst ,  carnelian ,  chalcedony ,  chert  (various colors), jasper-like flint,  jasp-agate, jasper,  Smoky Quartz crystals, clear  Quartz..
 ZANESVILLE, area mined deposits⎯Hematite.

OTTAWA COUNTY
  CLAY CENTER, area limestone quarry, famed ⎯Calcite,  Celestite (fluorescent), Dolomite crystals,  Fluorite (fluorescent),  Pyrite,  fossils.   GENOA, SE, in area quarries⎯Calcite,  Celestite,  Dolomite crystals,  Fluorite, Marcasite,  Pyrite,  fossils.
  GREEN (or Strontian) ISLAND, Put-in-Bay , Lake Eire, as fine crystals and large masses filling fissures in the waterline rock⎯Celestite.

PERRY COUNTY
 AREA:  c  countywide deposits, long worked, as nodules ⎯flint;  d  townships of Monday Creek, Salt Lick, Pike and Clayton, area⎯flint.

ROSS COUNTY
  CHILLICOTHE, W several mi., in a region  exposures of blue clay, as large masses⎯ Pyrite crystal clusters.

SANDUSKY COUNTY
  WOODVILLE, area quarries ⎯Calcite,  Celestite,  Dolomite crystals,  Fluorite, Marcasite,  Pyrite,  Witherite (fluorescent),  fossils.

SCIOTO COUNTY
  PORTSMOUTH, countywide regional quarries⎯Catlinite.

SENECA COUNTY
  MAPLE GROVE (N of Tiffin to Ft. Seneca on Rte. 53 and W 2 mi. on secondary line rd., then N ½ mi. to Maple Grove Quarry)  ⎯Calcite,  Celestite,  Dolomite crystals, Fluorite,  Marcasite,  Pyrite,  fossils, etc.
A Location Guide for Rock Hounds in the Untied States 339

TUSCARAWAS COUNTY
  CANAL DOVEL, MIDVALE, NEW PHILADELPHIA, ROSWELL, WAINWRIGHT,
regional mines ⎯Pyrite.

TUSCARAWAS, STARK, SUMMIT & PORTAGE COUNTIES
  AREA, from the NW part of Tuscarawas  Co., in numerous townships along the valley of the Tuscarawas R. from Bolivar to Zoar Station, as nodules in limestone outcrops⎯flint.

VINTON COUNTY
 AREA:  c  Swan Twp., on Upper Mercer horizon exposed along an old rd. in SE part of Sec. 9⎯flint;  d  townships of Richland (Sec. 1, central part along an abandoned rd.), Wilkesville, Vinton, Clinton and Elk, in Vanport limestone exposures as nodules⎯flint.

WAYNE COUNTY
  AREA, Paint Twp., Sec. 24, near center, as black nodules ⎯flint.

WOOD COUNTY
  BOWLING GREEN, W and S, at the Pugh Quarry ⎯crystals of Barite (fluorescent), Calcite,  Celestite,  Fluorite,  Pyrite (all in cavities and veins).
  LIME CITY, area quarries ⎯Celestite (fluorescent)