"It is very difficult to trace and verify this rock's complete history, but the inheritance of the stone was clearly documented in the family genealogy books of the last few collectors from the Qing Dynasty (1644-1911)," Shi says.

According to folklore passed down for several generations, having the stone in the house would help the family to bear more male children. Traditional Chinese society preferred boys to girls, not just because men were capable of hard labor, but because they could carry on the family name.

"This legendary function could be the key reason that this stone has survived for 2,000 years," Hu wrote.