Tucson-based geologist Peter Megaw has led local efforts through the Tucson Gem & Mineral Society for many years to collect geology texts and references and donate them to a variety of Mexico universities. By donating your books and journals to the TGMS, which is a non-profit (501-C3) organization, you can also claim a deduction on your federal taxes. TGMS does not provide estimates of the value of your donation. That's up to you or you should get them appraised.
Peter invites you to contact him (+1 520-529-2231, office) and arrange to drop off your books at the storage unit where they are held until Peter delivers them to the schools in Mexico.
Peter shared that the IRS requires donations valued at more than $4,000 in any year, require a professional appraisal.