Xinhua has a report about artificial eggs that were apparently sold by a street vendor in Handan, Hebei Province. The report says that the man who took the eggs home found that the eggs' yolk and white were all mixed up, and di not have any flavor. After inspection by "relevant departments" it was found that the dodgy eggs' shells were made from calcium carbonate while the fake yolks were made from a mixture of gelatine, starch and other chemicals.

The Xinhua report in Chinese here, with a photo of the fake egg.