The $5,735,000 jewelry mirror on a home in the Virginia suburbs of Arlington caught fire, the Virginia State Fire Marshal’s Office said on Thursday.
Fire officials said the fire was not believed to be suspicious.
The home had been empty for two years, but fire officials said they did not believe the fire started there.
Fire investigators were still trying to determine if the fire caused any damage.
Firefighters have been on the scene since Thursday evening, and said they had not been able to stop the fire from spreading.
The fire destroyed the mirror, which is made of polished bronze.
It is part of a collection of jewelry that includes a silver pendant, a silver ring and a gold bracelet, the Arlington Fire Department said.