What does it mean when the word Onyx is used in association with a cable? At first, I assumed that Onyx was a trademark used by a corporation, that would stand behind the quality of their cables. But after searching for an "Onyx" company, I was not able to find anything. I also noticed that The trademark symbol was never present. The reason is that I have discovered a number of cheaply made cables from china. When those cables fail, I have done an autopsy to discover that the individual wires in the cables contain only a few strands of copper wire that are human hair thickness.

Looks just to be a trademark. If you want better cables you need more strands and/or lower SWG cable.

If it is a trademark who owns it?

Possibly not actually a specific trademark just a name used by a couple of companies. Much like Platinum Cable and the like -- used to show where it is in a range. In short -- marketing drivel that can safely be ignored.

It is a company, apparently based in the USA:
http://onyxcable.com/
Duckduckgo wins again!

Indeed, Google didn't seem to find it.

That is odd that Google did not find it but DuckDuck did. I've used both and always thought Google was better at finding stuff. Well maybe Google is not all it thinks it is.