TLD-700 Chips. Li(7)F Mg,Ti doped.
Note these chips have writing on them. The writing does not interfere with the reading. It was done by the previous user to keep track of them during experiments.
TLD-700 material uses isotopically enriched Li-7 and is neutron insensitive. These would make great extremity dosimeters since they do not respond to neutrons (no neutron extremity monitoring anyway).