The rock broke up into at least three large pieces as scientists began lifting it from the ground with the help of levers and ropes.
The scale itself broke the moment it hit the 570-kilogramme (1,255-pound) mark.
"The rock had a fracture when we found it," one unnamed scientists told the lifenews.ru website in a live transmission.
"It weighed 570 kilogrammes before the pieces fell off. And then the scale broke," said the scientist.
"We think the whole thing weighs more than 600 kilogrammes," he said.
Experts cautioned however that it will take time before scientists can certify that the rock they pulled from the lake had indeed come from outer space.
The Vesti 24 rolling news channel reported that divers had already recovered more than 12 pieces from Lake Chebarkul since the February 15 incident.
The station cautioned that only four or five them turned out being real meteorites.