Contemporary Counterfeit? 1824 5 Franc

I have a similarly underweight coppery looking 2F from 20 years later. The details are not sharp, like yours. I suspect that they were sharper before the silver plating was removed. I don't think these would have passed in commerce without looking like silver.

I believe all three coins are in fact contemporary circulating counterfeit types.

The 1824 appears to be a typical sand cast copy made using pre-1830 materials which would have been silvered after it was created. These were normally silver washed (more like a paint and meant to pass only one time). The silver layer was very thin and often wore off quickly. Silver amalagam is also possible but a bit less likely.

The 2 Franc coin is probably also a cast copy (hard to tell because the photo is not in sharp focus). However at that time it likely used a much better (finer grained) molding material of the type introduced after 1830. If it follows what I would call a "normal" type the core is nearly pure copper. It would likely have been electroplated.

The 1823 was likely made last. The metal has the color of any number of typical lead, tin and antimony alloys used in die casting a process that dates to the 1840s. This is still well within the circulating window and I have seen many of the type and they were very successful counterfeits. The silver coating is post creation and likely electroplate.

It would be interesting to XRF these three to confirm the diagnosis.

I should rephoto that 2F....some day....it's enough to show the mushy details under the plating and the coppery color. I bought it in a flip, but it was priced at silver melt.

One of the early engravers of California fractional gold was Deriberpe. I did a little digging and found that he was in and out of trouble with the law in France in the 1840's. Not too surprising to find him following the money, to make underweight quasilegal coins elsewhere. The new "jewelry" business lasted a couple years, and his name disappears from SF business records after 1855.