Ohio Flint Guitar Pick
27.42mm x 19.43mm and 2.26mm thick

In Ohio, flint occurs in nodules or beds in Devonian limestones (408 to 360 million years ago), and particularly in Pennsylvanian limestones (320 to 286 million years ago). These rocks were deposited in shallow, tropical seas that covered the area that is now Ohio during the Paleozoic Era. It is thought that the silica was derived from the siliceous spicules of sponges. The most conspicuous bed of flint is associated with the Pennsylvanian-age Vanport limestone at Flint Ridge in eastern Licking and western Muskingum Counties that covers a ridge top area of about 6 square miles and 8 miles long. The flint deposit ranges in thickness up to12 feet of high-quality flint. 
Ohio Flint can be worked into a variety of forms, and its surfaces will take a high polish. Small amounts of impurities commonly give a wide variety of colors to flint: red, pink, green, blue, yellow, gray, white, black. Some combinations of these colors in a piece of flint are considered to be very attractive.