Heart-Beast by Tanith Lee

1992 Dell SF hardcover edition in very good condition with some very light wear along the dust jacket extremeties. Nice bright copy with intact spine.  Cover art by Bryn Barnard. 
 
In the streets of the sukh, Daniel Vehmund moves among snake charmers and dagger jugglers. Wanted for murder, he travels the world, lured on by a brilliant diamond and a curse, caught in the sway of every full moon...

On a Mediterranean seacoast a death ship washes ashore, and the tide takes it out again, cleaned of its bloody cargo...In the frozen West, a woman, trapped in a loveless marriage, receives a rare diamond from her husband. It has a flaw in its center that looks almost like a wolf.

Unknowingly, she awaits the beast, and will be drawn to him as he is drawn to her. Until a deadly sliver of meteorite in the snow sets them both free...

In the snow-covered forest the beast lifts his heavy head. He kills and is unkillable. He is beautiful and horrific. He is the fear and the power, the envy and the magic and the desire. And he has come home to claim his place at last...