Crystallography is a book of poetry and prose published in 1994 and revised in 2003 by Canadian author Christian Bök. Based around a pataphysical conceit that language is a crystallization process, the book includes several forms of poetry including concrete poetry, as well as pseudohistorical texts, diagrams, charts, and English gematria. An important illustrative feature is the section entitled A Key to Speleological Formations, which compares each letter of the alphabet and punctuation mark to a rock formation, allowing each poem to be read as if it were a landscape feature.