New Jersey State Mineral: Franklinite

New Jersey's state mineral is franklinite, adopted in 2023.

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

Franklinite specimen — Franklinite (not necessarily from New Jersey). Photo: Robert M. Lavinsky, CC BY-SA 3.0, via Wikimedia Commons

State mineral: Franklinite

Adopted:: 2023
Law:: P.L.2023, c.110, approved July 19, 2023

Franklinite is a mineral with a Mohs hardness of 5.5–6 and a metallic luster, usually black.

How to identify franklinite →

Often confused with: Magnetite

New Jersey state symbols FAQ

What is the state mineral of New Jersey?

New Jersey's state mineral is franklinite, adopted in 2023 (P.L.2023, c.110, approved July 19, 2023).

Sources

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

P.L.2023, c.110 (S1727), designating franklinite as the State mineral — New Jersey Legislature (accessed 2026-10-23).

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

Think you could spot these from a blurry close-up?

Play today's Rocksday