Cause of rocks igniting in O.C. woman's pocket remains a mystery
Scientists remained puzzled Friday over what caused rocks picked up on San Onofre State Beach to ignite in the pocket of a woman's cargo shorts.
The 44-year-old San Clemente woman, who has not been identified, went to the beach Saturday with her family, and her children collected colored rocks. The woman took the rocks from her children, put them in her right pocket, and the stones ignited after they returned home, authorities said.
Capt. Marc Stone of the Orange County Fire Authority said paramedics arrived to find the woman had suffered second- and third-degree burns from her right thigh to her right knee, as well as second-degree burns on her right hand.
The woman remains hospitalized. Her husband also had burns on his hands after attempting to help her.
The Orange County Health Care Agency was called in to examine two of the rocks, one of which was large and gray with orange streaks and another an emerald color also flecked with orange. Tests revealed a "phosphorous substance" on the rocks, which have been sent to a state laboratory for further testing, said Tricia Landquist, an agency spokeswoman.
Andrew Borovik, a professor of chemistry at UC Irvine, said phosphorus can remain stable under water and then can ignite once it touches the air. But he said he was unsure how the phosphorous substance could become part of a rock.
"I don't know if it exists just sitting around on the beach," Borovik said. "It just seems unlikely."
Larry Overman, also a professor of chemistry at UC Irvine, said he found it difficult to believe such chemicals could be in such a setting. Another unanswered question, he noted, was what caused the rocks to ignite when the woman had taken them home later in the day, rather than earlier on the beach.
"I can't think of a scenario of chemicals on the beach that would have the properties that are described," Overman said. "It's pretty implausible."
-- Rick Rojas