Large vintage Mexican sterling silver Mayan calendar brooch or pendant.  It has a silver pin and rollover C clasp closure to the rear as well as a pendant bail. It  is marked "STERLING 925 MEXICO" and "83" on the rear. The brooch measures approximately 5.9 cm in diameter. Weight is 22 grams. It is in very good condition.
 

Condition: Very good 
Colour:Silver
Metal:Sterling Silver
Size: 5.9 cm in diameter
Era: Estimated 1960's to 1970's