Vintage Gold Rush Nuggets on Fossil Sterling Silver Screwback Earrings

Likely a Yukon or Alaska gold rush souvenir item. These likely date to the 1940’s or so. The little nuggets are set onto a darkened fossilized bone type material that only shows that dark at the front surface They have a partial Sterling mark on the back of each as shown in the photos The silver has patina and it looks like they are vermeil: gold over sterling 5/8” in diameter 5.3 grams for the pair Pretty close to officially antique!