In the niu chapter Chalchihuitzli ('Precious Stone of Sacrifice') was mentioned, and for various reasons there is reason to repeat the story:

"...the great high priest and monarch of the Golden Age in the Toltec city of Tula, the City of the Sun, in ancient Mexico, whose name, Quetzalcoatl, has been read to mean both 'the Feathered Serpent' and 'the Admirable Twin', and who was fair of face and white of beard, was the teacher of the arts to the people of pre-Columbian America, originator of the calendar, and their giver of maize.

 

His virgin mother, Chimalman - the legend tells - had been one of the three sisters to whom God, the All-Father, had appeared one day under his form of Citlallatonac, 'the morning'. The other two had been struck by fright, but upon Chimalman God breathed and she conceived. She died, however, giving birth, and is now in heaven, where she is revered under the honourable name of 'the Precious Stone of Sacrifice', Chalchihuitzli.

 

Quetzalcoatl, her child, who is known both as the Son of the Lord of the High Heavens and as the Son of the Lord of the Seven Caves, was endowed at birth with speech, all knowledge, and all wisdom, and in later life, as priest-king, was of such purity of character that his realm flourished gloriously throughout the period of his reign.

 

His temple-palace was composed of four radiant apartments: one toward the east, yellow with gold; one towards the west, blue with turquoise and jade; one toward the south, white with pearls and shells; one towards the north, red with bloodstones - symbolizing the cardinal quarters of the world over which the light of the sun holds sway."  (Campbell)

 

The complete myth can be read in the Index under Quetzalcoatl and Tezcatlipoca (alternatively at hahe).

In an extraordinary picture of myth Chalchihuitzli appears together with a person (of obviously central importance) who has a twisted body shape:

She is here the Aztec version of Chalchiuhtilicue as she was called in their language:

"... In Aztec mythology, Chalchiuhtlicue (also Chalciuhtlicue, or Chalcihuitlicue) ('She of the Jade Skirt') was the goddess of lakes and streams. She is also a patroness of birth and plays a part in Aztec baptisms. In the myth of the five suns, she had dominion over the fourth world, which was destroyed in a great flood. She also presides over the day 5 Serpent and the trecena [a 13-day period] of 1 Reed.

Her husband was Tlaloc and with him, she was the mother of Tecciztecatl and ruler over Tlalocan. In her aquatic aspect, she was known as Acuecucyoticihuati, goddess of oceans, rivers and any other running water, as well as the patron of women in labor. She was also said to be the wife of Xiuhtecuhtli. She is sometimes associated with a rain goddess, Matlalcueitl.

In art, Chalciuhtlicue was illustrated wearing a green skirt and with short black vertical lines on the lower part of her face. In some scenes babies may be seen in a stream of water issuing from her skirts. Sometimes she is symbolized by a river with a heavily laden prickly pear tree growing on one bank ..." (Wikipedia)

The curious man in the middle of the flowing tail of Chalchiuhtlicue shows by his legs at left that he must be swimming on his back (tu'a), but at right he is turned around with his stomach below.

I can count to 13 'flames' issuing from her long flowing 'skirt', and in addition there are 16 sun symbols. 13 + 16 = 29, suggesting Moon.

Moving from top left and counterclockwise sun symbols and 'flames' (maybe droplets?) alternate in a regular pattern (with a sun symbol arriving before a 'flame'). After the 7th sun symbol, however, another sun symbol (the 8th) arrives. Equally: after the 13th 'flame' the 15th sun symbol is followed by another (the 16th) sun symbol. We recognize 8 and 16 as cardinal numbers from the rongorongo texts.

The crack in the body of the swimmer (Sun) comes after 3 segments, and then follows 4 more. (They cannot be ribs, because such are 2 * 12 = 24 in number.) He represents the year and his position is midsummer. Spring is in the past (therefore at left and on its back) and autumn lies in front. Further on is a mysterious coffer, maybe a coffin, for the time when he becomes tired and his face will fall down.