Please forgive the poor quality scans. A friend sent them to me with some questions that I am unable to answer, so I'm posing them here in the hopes that someone can give him some answers. The first coin was an underweight Athenian Owl that I wrote about in a separate thread. Here's the second coin: This is what he wrote about this coin: Perseus, son of Philip V, obv. Perseus diademed head right, beard worn, rev. ΒΑΣΙΛΕΩΣ ΠΕΡΣΕΩΣ, it has the monogram between the legs AN, and HP to the right, and is surely the coin of Perseus of Macedon, Wildwinds Mamroth 15. The outer ring of laurel wreath is missing as the coin is small, 22 mm, and weighs only 12.37 g, tetradrachms of Perseus like this weigh about 16.8 g. The patina and wear on this coin looks good, inscription is deep and clear. Here are the results of an (amateur) specific gravity test that he conducted: 13.36g dry 1.31 suspended weight 10.19 sg .800 fine silver Tetradrachms of this kind at CNG weigh 16.8 g., but .800 fine silver is only a little low, while total weight is low. Wildwinds cites Mamroth 15 for the inscriptions. Or it is not authentic. Anyone have any ideas that I can share with him about why this coin is underweight?