The state of Ohio declared flint as the official gemstone in 1965. Flint is a type of quartz which falls in the cryptocrystalline variety. It is available in abundance in Ohio, especially in the central and eastern counties of the state.
There are many other minerals which can be found in different areas of Ohio including nice specimens of calcite, celestite, fluorite, and many different fossil varieties.
The Vanport flint of the Pennsylvanian age which is the most well known flint of Ohio is available in Muskingum and Licking counties in the area of Flint Ridge. The Native Americans used the flint for making spear points, arrowheads, knives and other ceremonial objects. The Vanport flint is generally found in light shades of yellow, red, green and few other colors.
Flint is a variety of quartz with impurities that give it the varied colors. Collectors often make colorful jewelry out of polished flints from Ohio, and flintknappers still make arrowheads with this material.
Calcite is found in western and central parts of Ohio. Calcite may be found in clear form and also in golden and dark brown colors. Calcite is found in some other places in Ohio such as Pugh Quarry and Lime City in Wood County. It has also been found in Maple Grove Quarry of Seneca County.
Allen County in northwestern Ohio has calcite and many other minerals and is an extremely popular site for rock collectors.
Celestite, or celestine as it is also known, is present in a few places in north western Ohio. The mineral is generally found as white or light blue crystals. It is a source of strontium and is widely used commercially in the making of fireworks and flares.
Large crystals of Celestine have been found on South Bass Island in the western part of Lake Erie in Ottawa County. The mineral has also been found in several other locations in Ottawa and Wood Counties.
Fluorite is found at many locations in Ohio. The mineral is generally found in brown colors and is occasionally found in yellow, purple and green colors also. The Findlay Arch Mining District in Allen County is a popular site for the mineral.
Fluorite is normally found with calcite and some other minerals. Other places in Ohio where the mineral is found are Pugh Quarry in Wood County, Auglaize Quarry in Paulding County. Fluorite specimens have also been found near Gibsonburg in Sandusky County and on Franke Island in Lake Erie.
Sphalerite is a mineral composed of zinc sulfide and has impurities of iron in it imparting the crystals colors such as deep red and reddish brown. Sphalerite in Ohio is found in the dolomites present in the southern part of the state which belong to the Silurian period.
The mineral is used primarily as a commercial source of zinc, although some high grade pieces can be crafted into gemstones or sold as specimen pieces. The locations where sphalerite has been found is at the Maumee Stone Quarry in Lime City area and at Pugh Quarry located in Wood County.
There are actually some decent placer gold deposits that can be found in Ohio. This gold actually did not originate in Ohio, but rather it was carried down by glaciers from rich gold bearing areas in Canada.
These glacial events occurred several times throughout history, dating back to the most recent ice age and many other ice age events that routinely moved glaciers southward through the Midwest.
Identifying terminal moraine areas where the glaciers melted and dropped material into waterways is the best way to find the better gold bearing areas. The gold concentrates in placer deposits within creeks and streams. The gold is usually very fine textured, so careful gold panning is required to capture these fine gold deposits.
More about Glacial Gold Deposits in the Midwest
Isotelus which is a species of the trilobite family was designated as the official state fossil of Ohio in 1985. These marine species were made up of a hard shell on the outside and lived around 440 million years ago. These fossils have been found at the site of Huffman Dam close to Dayton.
Some other fossils such as brachiopods, horn coral, crinoids and bryozoans which belonged to the Devonian, Silurian and Ordovician eras can be found at Trammel Fossil Park, Fossil Park in Sylvania and Oakes Quarry Park in Fairborn in Ohio.