This handbook is a compendium of nuclear data to be used for neutron borehole logging and neutron activation analysis of mineral samples, meeting the major requirements of the nuclear geophysics community for microscopic cross-section and decay data. Contents: Chapter 1. Introduction; Chapter 2. Table of nuclides; Chapter 3. Prompt gamma rays from thermal neutron capture — Extracted from the database; Chapter 4. Nuclear decay gamma rays with intensities higher than 5% — An extract from the ENSDF radioactivity database; Chapter 5. Spectra of neutron sources; Chapter 6. Neutron induced reaction cross-section data for nuclides required for borehole logging and mineral analysis; Chapter 7. Neutron source averaged cross sections.