Ohio flint was designated the official state gem stone of Ohio in 1965. Large quantities of this gem can be found in Ohio, especially in the eastern and central parts of the state. Used to make jewelry and highly prized by collectors, Ohio flint comes in a variety of color combinations that include red, pink, green, blue, yellow, gray, white, and black.

Flint is a type of quartz, a hard and durable mineral. Native Americans used flint to make a wide variety of tools, weapons, and ceremonial pieces such as knives, arrowheads, and pipes. Early European settlers of Ohio also used flint for objects like millstones and rifle flints.

Flint Ridge (in Licking and Muskingum Counties) was a major source of flint for Ohio's Indians, who traded flint with other Native Americans across the continent. Archaeologists have discovered artifacts made from Flint Ridge flint as far west as the Rocky Mountains and south to the Gulf of Mexico.

Source:

Ohio's State Gemstone - Flint: Ohio History Central

Links:

Geological Symbols - 50 States List