[jacquesm]

But that first contact point transistor, even if it degraded rapidly actually worked, the challenges were to package it properly and to make it smaller and more reliable. This stuff, assuming it is all true is more at the level of the first inkling that semiconductor diodes might be a thing. We still have to reach that transistor stage (which would mean we an expensive way to manufacture a small stretch of usable conductor, say a few cm). Then you can start thinking about high volume production in any desired length and commercialization. So from a strict materials science point of view there is still a ton of work to be done even if everything so far turns out to be true. There is a good chance that even if the material isn't superconducting in bulk small regions of it are (the chances of that are actually higher than that it is all superconducting) and there is still a good chance that they are simply mistaken.

But even if it is just superconducting grains smaller than a millimeter that would already be a massive discovery.

[regularfry]

If it has superconducting grains but isn't superconducting in bulk, is it likely that those grains could be separated, oriented, and combined to make a bulk superconductor?

Because I can guess how you'd go about doing the first bit: crush it, put a magnet under it, and scrape off any bits that float...