What is the story with this unusual ring? Why is it in the Karshner Collections?

John Franklin Karshner, father of museum founder Warner Karshner, came west to the Pacific Northwest from Ohio several years before Warner and the rest of his family. After some time, he staked another claim to some land in Alaska, where he mined for gold. This ring is set with a nugget he found there. He presented it as a gift to his daughter Zura, and many years later, her daughter donated it to the museum!