I dimly remember a scene in a Darkover novel that I read in the early 1980s. A character visits the Darkovan equivalent of a gypsy fortune teller kiosk with a crystal. The fortune teller, an elderly woman, holds the crystal to her head and consequently dies in terror. I think it might be The Bloody Sun, but I read a synopsis of it recently and none of it rang a bell.
This is indeed The Bloody Sun by Marion Zimmer Bradley
Kerwin goes to have his fortune told.
The crystal on the table, his own crystal, glowed and shimmered; the crystal in the wicker frame, between the woman’s slender hands, began slowly to glow with blue fire.
The woman screams, the crystal cracks and...
Kerwin looked down at the woman, angry and puzzled. She had shown him something—but what did it mean? Why had he screamed? He felt cautiously at his throat. His voice felt frayed.
“What the hell was that all about? I suppose the dark man was my father. But who were the others?”
The woman neither stirred nor spoke, and Kerwin scowled. Drunk, drugged? Not gently, he reached to shake her shoulder. “What was that? What did it mean? Who were they?”
With nightmarish, slow grace, the woman slid down and toppled sideways to the floor. Swearing, Kerwin vaulted the table and knelt at her side, but he already knew what he would discover.
The woman was dead.