Comment by genewitch

Aka orbees. Also useful as a soil amendment if you have clay soil, it stops it from claying so much and retains water underground for plants.

They make glow in the dark ones, which I put into a masonry jar with some distilled water and a drop of bleach, I light it from underneath with a USB LED and it glows for about an hour. Cool night time light.

Back in the early 90s they had a different name and they were irregularly shaped. This was for Soil Amendment. I think it started with a Z.