This is a storage container, known as a pig, intended for safely holding highly radioactive isotopes used in the medical field for treatment and diagnosis. It's made of tungsten, which is somewhat unusual for a shield, lead and depleted uranium being more common shielding materials. But it makes sense, all these metals are good shields mainly because they are very dense, which is another way of saying lots of atomic nuclei packed into a small space, the better to block fast-moving decay products.
The person I got this pig from has many more like it, as well as other kinds of lead and tungsten shielding products. He doesn't want to be identified publicly, but contact me if you'd like to buy similar objects from him and I can put you in contact. Click the Source link below to see other kinds of things he has available.
Contributor: Theodore Gray
Acquired: 11 August, 2007
Text Updated: 8 December, 2007
Sample Group: Medical