100 Francs Pasteur

What sets the 100 Francs Pasteur coin apart is that it was one of the first French issues to depict a real scientist, Louis Pasteur, on its obverse, breaking from the tradition of monarchs and goddesses. This 1923 commemorative was struck in gold at the Paris Mint, using alloy standards typical of the era to honor the centenary of Pasteur's birth. The design, by engraver Jules Coutan, features a detailed portrait on the front and a Pasteur Institute emblem on the reverse, making it a straightforward tribute rather than the overblown legends some attach to it.

Production numbers are murky; official records from that period were often inconsistent, and I've seen estimates vary wildly based on auction data. What I can say for sure is that it circulated briefly before being hoarded, given France's economic turbulence post-World War I. Not every coin needs a dramatic backstory.

As for its physical traits, the coin weighs about 6.45 grams and has a diameter of 21 millimeters, hallmarks of the French gold franc series. I once handled one with a subtle die crack, a common flaw that reminds you even commemoratives aren't perfect.