Hmm, I wonder what the glaze is on the light green tile on my pond, seems like the Geiger counter clicks a bit more next to it. Installed in 1978... were they still using something with radionuclides for green glaze in the 70's? 🤔
@ai6yr wikipedia says that it wasn’t until 1987 that the know it stopped
“In 1987, NCRP Report 95 indicated that no manufacturers were using uranium-glaze in dinnerware”