Lucky stone

A lucky stone is actually the unique ear bone or otolith of a freshwater drum (Aplodinotus grunniens), also known as the sheephead fish.

In times past they have been worn as protective amulets, made into jewelry, and traded into areas far from the fish's native range (such as Utah and California).

Lucky stones (otoliths) have been found at ancient archaeological sites, where they are thought to have been used as good luck charms to ward off illness.

[1] University of Minnesota Biologist George R. Spangler gives a technical explanation of the "letters" which appear on the lucky stone.

David Starr Jones notes that "the otoliths of the river-drum are known to Wisconsin boys as 'lucky stones' each having a rude impress of the letter L."[3]