Andre Norton, 2008 (Originally 1968, 1969)
Premise: Originally published as Uncharted Stars and The Zero Stone. When his father died, Murdoc Jern was left with very little. He had an apprenticeship to another gem trader and a ring of unknown material found in deep space. Circumstances and a new friend will cause him to undertake a desperate search for the zero stones; source of power and magnet for violence.
This was a re-read for me, I had these books when I was young and they were some of my favorite Andre Norton books I'd read. I still think they're good, although a character who's an alien space cat with psychic abilities is less of an instant draw for me than it once was.
Murdoc is a space trader; he's not in the business of cheating others but isn't any sort of paladin, he's just trying to survive. I like how underplayed the friendship between Murdoc and Eet is. Murdoc sometimes resents Eet's high-handed treatment, Eet sometimes comments that it's just a mutually beneficial partnership, but they're still quietly fond of each other.
The plot moves at a decent clip, and the description is pretty stripped down. Published separately these were both very short books, and as a close-knit duology, I'm not surprised that they've been packaged together.
I think the end is sort of anticlimactic, but it's still a lot of fun along the way.
4 Stars - A Very Good Book