Savor the product description for this item that’s on sale via Amazon.com:
with Section 13 from part 40 of the NRC Nuclear Regulatory Commission rules and regulations and Postal Service regulations specified in 49 CFR 173.421 for activity limits of low level radioactive materials. Item will be shipped in accordance with Postal Service activity limits specified in Publication 52. Radioactive minerals are for educational and scientific use only.”
(Thanks to investigator Alphonso Lopez for bringing this to our attention.)
