This is another piece given to me by my Mother. It appears to be stamped 825 rather than 925. It polishes like 925 and is sterling silver. I’m not completely familiar with the time period this would have been made or why it would be 825 vs 925 other than it may be less expensive to produce since it would be 82.5% purity vs the 9.25%. This is a really cool piece, as the clam shell holds a silver ball inside that makes sound when moved. I included a video along with pics. Measurements 1.5”x1.5” Weight 20 Grams