Walter Borchardt-Ott. “Crystallography”. 1993. ISBN 3-540-56679-1.
Hands down best book on symmetry. Clear, methodical, thorough. Just buy it.
Gregory S. Girolami. “X-ray crystallography”. 2016. ISBN 978-1-891389-77-1.
If you are going to buy one book on crystallography – this is it.
Werner Massa. “Crystal structure determination”. 1999. ISBN 3-540-20644-2.
A very popular introductory book.
Jenny Glusker, Mitchell Lewis, Miriam Rossi. “Crystal structure analysis for chemists and biologists”. 1994. ISBN 0-89573-273-4.
An excellent, if somewhat dated, crystallographic text covering all aspects of single-crystal X-ray analysis.
Maureen M. Julian. “Foundations of crystallography with computer applications”. 2008. ISBN-13: 978-1-4200-6075-1.
The book clearly explains matrix use in crystallography, both for unit cell transformations and for generating symmetry-related positions.
Vitalij K. Pecharsky, Peter Y. Zavalij. “Fundamentals of powder diffraction and structural characterization of materials”. 2009. ISBN: 978-0-387-09578-3.
Excellent thorough text on X-ray powder diffraction.
George H. Stout and Lyle H. Jensen. “X-ray structure determination. A practical guide”.1989. ISBN 0-471-60711-8.
A favorite of seasoned crystallographers with an excellent Fourier transformation section.
C. Giacovazzo, H. L. Monaco, D. Viterbo, F. Scordari, G. Gilli, G. Zanotti, M. Catti. “Fundamentals of crystallography”. 1998. ISBN 0-19-855578-4.
A fundamental and very technical tome.
Peter Mueller, Regine Herbst-Irmer, Anthony L. Spek, Thomas R. Schneider, Michael R. Sawaya. “Crystal structure refinement. A crystallographer’s guide to SHELXL”. 2006. ISBN-13: 978-0-19-857076-9.
A very good practical guide for single-crystal X-ray structure refinement with an excellent section on twinning.
Elizabeth A. Wood. “Crystals and light. An introduction to optical crystallography”. 1964. ISBN 0-486-23431-2.
If you want to know how to look at crystals – start with this book.