Found: Romance Novel?

I'm trying to find an adult romance novel I started reading a few years back and never finished. It has a red cover and it's about a woman named Kate who cuts gemstones. I think there might have been a love triangle and possibly a murder? Please help

Possibly The Color of Death by Elizabeth Lowell?

YES THAT'S IT! THANK YOU SO MUCH

>3 frappuccino4576: Happy to help! :-)