Destroyer by Meg Smitherman

Thrown together by fate…
At the center of a forbidden ruin, an artifact of black stone is unearthed.
Archaeologist Ru Delara, vilified by the scientific community for believing in magic, is summoned to investigate. But when she arrives, she finds herself inexorably drawn to the artifact, even though it could harbor untold destructive power.
Unable to resist its pull, Ru reaches out to touch the stone…
Waking in the dark, naked and alone, Ru sees that everything and everyone within a mile radius has been vaporized. Only she and the artifact remain intact. When a windswept stranger called Fen finds her in this vulnerable state, she has no choice but to accept his help.
Determined to discover the artifact’s true nature, Ru and Fen travel to the Cornelian Tower, the scientific heart of the kingdom. But conspiracy brews in the capital city, and it’s clear that Ru isn’t the only person with a vested interest in the artifact.
Drawn into a conflict they hardly understand, all while contending with a profound and consuming mutual attraction, Ru and Fen must unravel the secrets of the artifact before it falls into the wrong hands… before its darkness engulfs them all.