Permanent claim record · Petoskey, Michigan

The Petoskey Stone — Michigan's official state stone since 1965 — is a fossilized coral (Hexagonaria percarinata) unique to Michigan's glacial geology that appears gray when dry but reveals hexagonal patterns when wet.

Verified\u00b7 1965-01-01
Raw value (vault-stripped) {"tags":["petoskey-stone","state-symbols","fossils","geology"],"text":"The Petoskey Stone — Michigan's official state stone since 1965 — is a fossilized coral (Hexagonaria percarinata) unique to Michigan's glacial geology that appears gray when dry but reveals hexagonal patterns when wet.","as_of":"1965-01-01","category":"nature"}
Predicatetrivia.fact
SubjectPetoskey, Michigan (place)
As of1965-01-01
StatusVerified
SourceWest Michigan Tourism: Attractions, Landmarks & Regional Highlights — Perplexity Deep Research (March 2026) (trust 6.5/10)
Reference—
Document hashpending evidence-pack link
Provenance chain
Claim ID25c51bfd-2f37-44c1-8609-4d80528704ab