Two dozen chunks covered in epoxy. They were the byproducts of scientific analysis. The lab was going to throw them away, but I got to keep them.
Each one is a cuboid. They were cut out of larger rocks that the lab wanted to analyse under a microscope. Glass microscope slides were glued to their bottoms and the rest of their surfaces were covered with epoxy. Each one then had a sliver sliced off their bottom for the microscope to see. Once the sliver was cut off, the rest of the rock was thrown away.
These leftover rocks – "billets" – are beautiful chunks of rock with perfectly smooth bottoms. I keep some on my desk to admire, and I use the rest as paperweights. I'll gift some to my friends when the time is right. The scientists in the lab call these rocks "waste material", but they've found a home with me.