Ohio State Gem: Ohio flint

Ohio's state gem stone is Ohio flint, adopted in 1965. Ohio's state invertebrate fossil is Isotelus, adopted in 1985. Ohio's state fossil fish is Dunkleosteus terrelli, adopted in 2021.

Symbol names and dates are taken from primary state sources linked below. Informal or proposed symbols are not listed unless adopted.

Chert specimen — Chert (not necessarily from Ohio). Photo: Unknown, Public domain, via Wikimedia Commons

State gem stone: Ohio flint

Adopted:: 1965
Law:: R.C. 5.07, effective August 24, 1965
Variety:: Ohio flint

It is a variety of chert. Chert is a sedimentary rock with a Mohs hardness of about 6.5–7 and a waxy to dull luster, usually gray, black, brown or white.

The statute describes it as a crypto-crystalline quartz.

How to identify chert →

Often confused with: Agate, Flint, Jasper

Also an official symbol of: Missouri

Trilobite specimen — Trilobite (not necessarily from Ohio). Photo: James St. John, CC BY 2.0, via Wikimedia Commons

State invertebrate fossil: Isotelus

Adopted:: 1985
Law:: R.C. 5.071, effective September 19, 1985
Variety:: Isotelus, a trilobite

It is a kind of trilobite. Trilobite is a fossil with a Mohs hardness of about 3–4 and a dull to vitreous luster, usually black, gray or brown.

How to identify trilobite →

Often confused with: Brachiopod, Eurypterid

Also an official symbol of: Rhode Island, Wisconsin

State fossil fish: Dunkleosteus terrelli

Adopted:: 2021
Law:: R.C. 5.078, effective March 24, 2021

Ohio state symbols FAQ

What is the state gem stone of Ohio?

Ohio's state gem stone is Ohio flint, adopted in 1965 (R.C. 5.07, effective August 24, 1965).

What is the state invertebrate fossil of Ohio?

Ohio's state invertebrate fossil is Isotelus, adopted in 1985 (R.C. 5.071, effective September 19, 1985).

What is the state fossil fish of Ohio?

Ohio's state fossil fish is Dunkleosteus terrelli, adopted in 2021 (R.C. 5.078, effective March 24, 2021).

Sources

We cite primary sources (statutes, state government pages, federal regulations, and land-manager sites). Third-party listicles are not used as citations.

Ohio Revised Code chapter 5 (§ 5.07 gem stone, § 5.071 invertebrate fossil, § 5.078 fossil fish) — Ohio Legislative Service Commission (accessed 2026-10-24).

Last verified 2026-10-24. Corrections welcome: if a statute has changed, tell us and we'll re-verify.

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