what rock is this?

Forty-eight things you can pick up on a Michigan beach, every one with the single observation that separates it from the stone it gets confused with. No app required, no guessing, no photograph of a rock fed to a machine that will confidently tell you the wrong answer.

a field reference, not a geology text · sorted by how often we turn one up

BEFORE YOU FILL A BUCKET

On land the Michigan DNR owns or controls, which is state parks and recreation areas, state forest, game areas and state-owned Great Lakes bottomlands, the limit is 25 pounds per person per year. That is everything combined, rocks and minerals and invertebrate fossils together, for your own use and not for sale. It is one allowance, not one per stone.

In a national park it is nothing at all. That includes Sleeping Bear Dunes, about thirty-five miles of mainland shore across Leelanau and Benzie plus the Manitou Islands, and it includes Pictured Rocks and Isle Royale. National wildlife refuges are the same, and the tip of Whitefish Point is one of them, the Whitefish Point Unit of Seney, sitting alongside parcels held by the shipwreck museum and Michigan Audubon. Most Keweenaw mine rock piles are private ground, a few of those owners sell dig passes, and others sit on DNR land or inside Keweenaw National Historical Park, so find out whose pile you are standing on.

Take what you love, leave the rest for the lake.

grail

ultra rare

rare

uncommon

the fossils

the bedrock

Keep track of what you find

The Rock Journal is a free field journal for your finds. It does not identify anything. It records what you found, where and when, and turns it into a card the rock groups can actually answer. Nothing leaves your phone unless you send it.

open the journal · free