I was recommended this book by a local librarian, who said she really enjoyed this author and described this book as 'mystical; involving magical gems and warring tribes'. So maybe she was thinking about another Quick book?

This was a pretty standard romance book for me. Read it on vacation, wasn't super invested nor interested.
Two main characters start out disliking each other, agree to become betrothed which will obviously not be as temporary as they originally intend, and they fall in love in the end.
Hugh the Relentless was all tell, minimal show of why he was so fearsome and scary. It would have been interesting to see his cruelty/ruthlessness and have the main girl (can't even think of her name) have to work to overcome this part of his personality. Plus he loved her essentially immediately and for no reason other than her beauty.
The main girl is immediately described as being super competent and very intelligent and highly educated for her female status during this time setting, yet she rarely if ever demonstrates this, rushing into situations without thinking and then being like "well, I knew you'd be there to rescue me, and ooh look, something shiny" topic dropped.
The sex scenes were meh, not particularly steamy to have sex in some dark dank cave.
I think the talk of "the stone" and all it's properties and how other stones have other properties COULD have been interesting, but was too vague. Instead of attributing crystals magic or healing powers or some significance, all stones were mentioned in ways like "she had yet to unravel its secrets". Huh?
The plot was so so. I didn't care about the rivalry between Hugh and his family, nor particularly care when Main Character had to ride to save the day, this could have been maybe a little more shown so we saw the tension and cared. There were also timing issues, where in small details/dialogue it seemed little time had passed but then in more general passages of description it seemed like significant time had gone by. I also can't recall much "getting to know you"/insightful moments happening, which really you just need like 2 times where both the main characters have a thought "oh, so (s)he isn't like I thought, which make him/her interesting and/or appealing to me" to make the love believable in this genre.

Overall, it was perfectly fine, and I may even try another Amanda Quick, but it wasn't a great hit for me.