A space rock, part of the Speed exhibit, was stolen sometime between 9:30 a.m. and 2:30 p.m., according to police.
The meteorite, made of iron-nickel, is believed to have significant monetary value, Capitol Police said.
"The meteorite was inside a secure, metal display stand," Capitol Police said in a news release. "Museum employees discovered that the stand had been disassembled by removing one of the brackets."
The exhibit was in the main hall of the first floor of the museum at 2500 W. Broad Street.
Anyone with information is asked to call Virginia Capitol Police at (804) 786-2120 and ask for the on-duty investigator.