Saw this recently and couldn't find an explanation. Is it common? The coin is a 1871 Mexico silver 10 centavos
For the 19th century Mexican coins there are many mint marks, probably around 10 or so just estimating. That one stands for Zaragoza. I don't think any of them are super common but it varies by year.
ZsZ should be for Zacatecas, Mexico: KM#403 - As - Alamos KM#403.1 - Ca - Chihuahua KM#403.2 - Cn - Culiacan KM#403.3 - Do - Durango KM#403.4 - Ga - Guadalajara KM#403.5 - Go - Guanajuato KM#403.6 - Ho - Hermosillo KM#403.7 - Mo - Mexico City KM#403.8 - Oa - Oaxaca KM#403.9 - Pi - San Luis Potosi KM#403.10 - Zs - Zacatecas
It's actually Zacatecas. Found in Numista site that has info on mintage and says it has varieties but can't find anything about what kind of varieties : https://en.numista.com/catalogue/pieces15262.html KM #403.10 Google book on these coins (Look for 403.10)
Found this, but again nothing on the 1871 Zs. Yours could be the one and only that exists (okay, I'm hyping it). You might want to try contacting someone from this site : http://www.globe-treasures.com/mexrep.html (email is an AOL one, don't know if AOL email is still alive today)
As it has the letters ZsZ, it cannot be 1871 and must be 1885 or later. In reality it is the 1891 double S variety.
Jay, AOL is still alive these days, as I've been using it since 1993, back in the days of "dial-up" and the "pay-per-minute"...
