I’m at a conference the rest of the week and will return on Monday. In the meantime here’s something for y’all to ponder. I have no idea what they could be either and all I can add is that whatever they are, they weigh very little:
Bonus: You can see almost all the history of chemistry at Rice from this window.
My guess would be they are simply tags that would be attached to shop equipment to identify it as belonging to the shop.
I think you’re right.
If they have a number on the flip side, I would say they are tool chips. Assigned to a specific person or lab and used when tools are checked out of the “tool crib”.