I have many links to freely downloadable tektite papers on my reference list.
This page is dedicated to tektite web resources. Some sites are commercial, but buying or not the images are free to view (but subject to copyright). I am still working on this page, so this is just a start.
The Tektite Source - Great images and information on all tektites.
Tektite Inc - The best site to go to for Philippinite images (also Phiilippinites / Rizalites for sale)
Meteorites-For-Sale - Some excellent tektites for sale from the Daryl Futrell collection.
Meteorite Studies: tektites - a great introduction to tektites.
Chebska Panev - Moldavites by Cava (In Czech)
NASA Technical Server - Freely downloadable papers on tektites and much more!
Much, much more to come on this page - this is just a start!