The image labeled "Californium bullet" actually shows laboratory neutron sources that contain 5 mg of Californium. The rest of the "bullet" is actually a stainl

The image labeled "Californium bullet" actually shows laboratory neutron sources that contain 5 mg of Californium. The rest of the "bullet" is actually a stainless steel casing. The metal shaving further down the page are most likely microscopic, but as no length scale is given it is hard to estimate the mass.