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)

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Predicate	trivia.fact
Subject	Petoskey, Michigan (place)
As of	1965-01-01
Status	Verified
Source	West Michigan Tourism: Attractions, Landmarks & Regional Highlights — Perplexity Deep Research (March 2026) (trust 6.5/10)
Reference	—
Document hash	pending evidence-pack link
Provenance chain
Claim ID	25c51bfd-2f37-44c1-8609-4d80528704ab