Petoskey stone
Fossil
Also called Hexagonaria and Hexagonaria percarinata
About it
Pebbles of the colonial coral Hexagonaria: six-sided cells, each with a dark centre and radiating lines, clearest wet or polished. Michigan's state stone, found on Lake Michigan beaches; collecting is banned in Sleeping Bear Dunes.
- Type
- Fossil (coral)
- Group
- Rugose coral (coral)
- Colours
- grey, tan, brown, cream
- Transparency
- opaque
- Periods
- Devonian
Typical values: real specimens vary. For more, see mindat.org.