Strange Matter.

[Xyph]

I've read that strange matter (or quark matter, or the degenerate matter supposedly found at the center of neutron stars) could potentially be stable beyond the conditions in which it was formed, unlike neutronium, which is only maintained by intense gravity. So, I'm wondering, how likely is this? I've also heard that it could have "cannibalistic" properties, in that it would potentially convert all normal matter it came into contact with into more strange matter. How likely is this? Is there even any way to tell?

 

Out of interest, how dense would strange matter be (obviously very, but numerically)? How quickly would it be able to cannibalise ordinary matter? Could things be built out of it, or would it remain spherical?