Uranium Element Cube (2inch Autunite)

This Uranium Element Cube is comprised of a sample that is 50% uranium by mass and is a naturally forming crystal of Uranium. Natural uranium contains about 0.7% uranium-235 which is the fissionable isotope used in nuclear reactors. This sample has about 2.5 grams of autunite which translates to about 8.75mg of the same isotope that nuclear bombs are made out of! The remaining 99.3% is U-238, also known as depleted uranium. 

Uranium is a chemical element with the symbol U and atomic number 92. In its pure form, it is a silvery-grey metal but this sample is obviously not the metal form.  Uranium is part of the actinide series of the periodic table.Most people think of modern technology when they hear the word uranium since it is the key element in nuclear energy and nuclear weapons.  However, Uranium was actually used as far back as the middle ages as a color additive to glass.  RegulationsIt is not regulated by law because it is a natural crystal specimen.  It is license-exempt and considered a Radioactive Ore Sample or Naturally Occurring Radioactive Materials (NORM). That being said, Autunite is becoming increasingly hard to find and collect.