This is a very pure vapor-grown piece of Tungsten. It was grown for research on an internal mandrel through an unknown process, though almost certainly from tungsten hexafluoride either by hydrogen reduction or thermal decomposition. As you can see, it is long and hollow, closed on one side; I don\[CloseCurlyQuote]t know for sure, but I would guess that the lab was trying to see whether tungsten crucibles could be manufactured economically that way, though I am not sure. The outer surface has clearly been lathed; only the bottom retains its porous, almost soft surface characteristic of thick-film deposited metal.
In addition, the microstructure looks almost sintered; my guess is that they found it to possess similar mechanical properties but was less economical than simply sintering a similar structure, based on the time and equipment necessary for any sort of vapor growth as opposed to powder metallurgy. A very nice research sample nonetheless.