Depicts the seal of the United Mexican States.

The Seal of the United Mexican States is a modified version of the national coat of arms, with the addition of the full official name of the country Estados Unidos Mexicanos, in a semi-circular accommodation in the upper part of the seal. Current and past Mexican peso coinage have had the seal engraved on the obverse of all denominations.

The coat of arms depicts a Mexican golden eagle perched on a prickly pear cactus devouring a rattlesnake. To the people of Tenochtitlan this would have strong religious connotations, but to the Europeans, it would come to symbolize the triumph of good over evil (with the snake sometimes representative of the serpent in the Garden of Eden).

Xiuhtecuhtli performing the New Fire ceremony (Ceremonia del Fuego Nuevo) within an ornamental circle with denomination and legend inside and date below.

In Aztec mythology, Xiuhtecuhtli ("Turquoise Lord" or "Lord of Fire"), was the god of fire, day and heat. He was the lord of volcanoes, the personification of life after death, warmth in cold (fire), light in darkness and food during famine. The Nahuatl word xihuitl means "year" as well as "turquoise" and "fire", and Xiuhtecuhtli was also the god of the year and of time.

Xiuhtecuhtli was celebrated often but especially at the end of every 52-year period. This was the time the 365-day solar and the 260-day sacred calendars ended on the same day and the Aztec celebrated the Binding of the Years with the New Fire Ceremony. In order to perform the ritual, priests marched in solemn procession up the Hill of the Star on a peninsula near Culhuacán to wait for the star Yohualtecuhtli (either Aldebaran in the Taurus constellation or the Pleiades as a whole) to get past its zenith. Having ascertained this, they would tear out the heart of a sacrificial victim and kindle a flame in a small wooden hearth they placed inside the hole left in his chest. Priests used a drill method to generate this sacred flame. It was then carried on pine sticks to light the fires anew in every hearth, including the sacred braziers of perpetual fire, that numbered over 600 in the capital alone.