A cylindrical sculpture carved on the surface with several concentric circles in low relief: a small circle at the center followed by a ring, six trapezoids, a large ring, 28 smooth circles and eight sets of four bars distributed radially around the edge. The design is the conventional glyph that symbolizes the tianquiztli or market, as described in the chronicles and represented in the native pictographs. Besides indicating a market or tianquiztli, this glyph was used to represent toponyms or place names, like Tianquiztenco or Xaltianquizco, for example; it also appears as a tezcacuitlapilli or as a specular ornament that military and warrior deities carried in the small of the back, as seen in some reliefs and Mexica sculptures. According to historical sources, markets in large cities were closed spaces, located in front or next to the temples of the gods, they had an area dedicated to worship the image of the "god of markets and fairs", which was a low platform with a round stone carved with the glyph market, whose description corresponds to this beautiful monolith sculpted in Chalco. Arqlga. Bertina Olmedo Vera