Osmium Plasma Force Ball: What is it?

Back in high school one of my friends (who was a heavy reader of science fiction and drugs, I should probably point out) would always talk about “osmium plasma force balls” as being the ultimate weapon. I know that osmium
is an unusually dense element but I assume that this weapon had to involve something more than dropping a heavy metal ball on someone’s head. Are force balls of any kind something that theoretical physicists have speculated about
or are they just dreamed up by some sci fi author? If they might really exist, what are they, how would they work and what would they do? Would an osmium one be particularly nasty? Is the Pentagon up to speed on this stuff?
As an aside, where do you find osmium, and what do we normally use it for?

Osmium is one of the platinum group of metals and contender with iridium for the densest element, depending upon whose data tables you trust. Its uses can be found here. They are decidedly non-military. Its outstanding properties are density and chemical inertness.

I take a (possibly unhealthy) interest in exotic weaponry, including those from sci-fi which make reasonable extrapolations from our current understanding of physics, but I’ve never heard of these things. My guess is that they are plucked from some work of soft sci-fi. If your friend can’t give you an outline of how they work or what they’re meant to do, I’d call bullshit on him! And if that doesn’t work, quote Darth Vader:
“Don’t be too proud of this technological terror you’ve created. The ability to destroy a planet is insignificant compared to the Force.”
That should fix him.