Correct ID on circa 12th - 15th Century Gold Fiorino

Hello,

I'm posting here today in attempt to nail down the identification of what I think is a medieval gold coin from Florence. What I'm looking for mostly is a more narrow date range and mint mark.



The obverse reads: S ·IOHA-NESS· B (St. John the Baptist)

The reverse reads: +FLOR-ENTIA (Florence)

I have found numerous other examples of this type of coin through some thorough searching, but haven't found another example that features the 'S' on the obverse next to St. John's halo. Most examples I did find each had different designs in that same location, so I'm thinking it is perhaps a mint mark.

Other features were a coat of arms, other letters, flowers and designs I couldn't recognize in place of the 'S' on this coin. Some were actually just blank there as well.

If anyone can help out with any info on what the 'S' represents, or maybe even direct me to a link to a previous sale or a catalogue entry, I'd appreciate it very much.

Thanks,
Rob

My skills to understand latin are pretty rusty but seems to be a very distinct indicator of AD 1388 for coins issued in Florence. Here is a full text from Storia delle monete della repubblica Fiorentina.

Wow, very cool. Thanks Andy!

In all the searching I've done thus far, the most narrow date range I found was about 300 years and just that short passage seems to identify the year directly as 1388.

Any idea on the S 'mint mark'?

Sorry I sent you the wrong reference, this is the right one.



Actually this S is not a mint mark but the sign of an union that holds together to struck this coin. You can see in the text above the people (with their honorific titles) that formed that union. There are so many other unions that issued coin as you can see how many distinct signs exists on the coins of Florence.
Few of them to get the idea: