See an image that represents tzacualli in the Visual Lexicon of Aztec Hieroglyphs, ed. Stephanie Wood (Eugene, Ore.: Wired Humanities, 2020-present).
Mitoa in ascan, tetepe tzacuilli, itzacuil tonatiuh, yoan itzacoal metzli. = They are now called pyramids—the pyramid of the sun and the pyramid of the moon. [Dibble and Anderson translation.]
Florentine Codex, Book 7, Chapter 4.
auh neli melahuac. yninte tzacuali tepantli. = And it was certainly true that they made this great temple
Anónimo mexicano, ed. Richley H. Crapo and Bonnie Glass-Coffin (Logan, UT: Utah State University Press, 2005), 31.
itzacual tonatiuh = pyramid of the sun
Ronald W. Langacker, "Possessives in Classical Nahuatl," International Journal of American Linguistics 38:3 (July 1972), 173–186.
A glyph in the Codex Mendoza illuminates the term tzacualli: https://aztecglyphs.wired-humanities.org/content/tzacualpan