I borrowed this book from the library years ago in the early 2000s. I believe it was published sometime between 1970 and 1999. It was an adult fantasy novel and definitely not something you would recommend for kids as it contained violence, sexual assault, etc. I don't recall the name, but I do recall specific details.
The cover had: a snow covered fortress on it in the background and in the foreground was a man and woman standing on a ledge looking at it. The rest of the background was white. This cover was painted (done by an actual artist), not photoshopped. Given the age of the book, I believe this was the first edition cover. It was a thick book as well and a hardcover.
The setting (from what I can recall) was a standard fantasy setting. Low tech, nobles and peasants around, but most of it took place in a cold environment. I don't recall magic being prevalent in the story. There were no magic spells or anything commonly used. The only real magical element was a red jewel that allowed characters to see into the minds of other people or animals. At one point during the novel, the main male character uses the jewel to see into the mind of an animal and discovers that it's sentient. He decides to keep the jewel a secret because of this because the powers that be (a powerful church, if I remember right) would not want people to know about this.
The magic stone I can't quite remember if it was referred to as a jewel, gem, gemstone, or anything specific. I recall it being red and faceted but don't quote me on that. All I'm concrete about is that it allowed you to look into other people's minds and see things. At one point, the male protag looks into his wife's mind and sees her memory of being sexually assaulted.
The setting was on an Earth-like planet but there were no familiar countries or governments.
Some other story details I can recall: male protag and female protag are married early on in the novel. It was arranged but they're familiar and comfortable with each other. Female protag was sexually assaulted by another character and it's hinted that she is pregnant by this person but it's never confirmed if this is true or not. The character who assaulted her was put on trial but due to some meddling from a relative (an older woman, possibly an aunt, grandmother, or mother), he isn't sent to jail. He gets off with exile or some equivalent.
The novel prologue talks about a plague that struck the area several years prior and then skips ahead to the modern times.
I think the novel is part of a series and I believe the one I had is the first one, but I'm not sure if it's part of a trilogy or not.
That's all the details I can remember for now. If I remember more, I'll edit it. Any help would be great!