Antique silver powder compact with gold California overlay

This belonged to my mom and I wish I'd been able to ask her about it before she passed. It looks like it's silver with gold (leaf?) overlays of California and top highlights. It's been well-used. There are no markings that I can find, but I haven't emptied out the remaining power. The base is etched concentric circles. It's about 3" in diameter and 3/8" thick. I'd love to learn more about it if anyone has any additional information. Thanks