existance of this is questionable as every bit of matter we have ever discovered can be condensed. (Which includes stars, black holes, etc.) Having so much density means that it would also weigh an incredible ammount and be so hot that not matter what it is, it would evaporate and destroy everything within a huge radius almost instantly. It can also be used to over-exaggerate something.
”Imagine if we somehow managed to create and safely contain an ultra solid’.’