Carnelians is the 14th books in the Skolian Saga by Catherine Asaro, but not the last in chronological order. Not that it matters any more. What I really liked about this series was that each book was pretty self contained (with the exception of Skyfall and Schism which had to be read together), meaning you could read whatever books in any order without feeling left out. Unfortunately that self-containment of the books is gone. It's gone from an interconnected set of stories to mere chapters in a larger story.
I could not recommend reading Carnelians before reading the preceding two stories. And since I have an abhorrence for the last book (Diamond Star) it hurts me to say that that particular has to be read.
The book is miles better than Diamond Star, it gives forward movement to the relationship between the two empires (but is unfortunately, all about that). Instead of focusing on just one main character, Dehya, Kelric, Jaibriol III, Del-Kurj (ugh), and a new character, Aliana are all followed. It broke the story up. And there were a lot of loose ends tied up, but I know I'd be happier if she found a way to bring Jaibriol II and Soz back from Prism in their self-inflicted exile just to throw everything into complete chaos.
It's a good addition. It's more like a 3.5 star for me. The writing felt off to me, not as polished as before, and there was a lot less of the physics/hard science in this one. The prevalence of quis helped make up for that, since I really enjoy that system of influence/predictions/modelling/communication/etc.
I did like it. I more than liked it, but I didn't *really* like it. Although if I had read it right after Diamond Star I would have probably given it 5 stars.
I'll leave you with the most ridiculous snipped from the book. I nearly put it down after this, it just seemed so corny for the book."Nothing would ease his fisted anger, no matter how many providers he whipped, or how many of them he buried his cock inside of. Not even when their screams sent him into the highest transcendence." ugh