Before the Libertad, There Was the Onza

I ran across these at my LCS, and they were new to me. Issued by the Mexico City Mint, and colloquially referred to as the "Onza", these were the precursor to the Libertad. These were minted from 1978-1980, and each one contains an ounce of silver, but the composition is 92.5%. As a result, these weigh in at 33.625 grams, instead of the normal 31.1 you'd get in a traditional 3 or 4 nines pure round.

I can understand why they went away from this design. It doesn't have the panache of a winged woman. Still, it's historical silver, so it's for me. Here's a few close up shots. I played with the lighting a bit to try to get the details to pop.