A Shandong farmer may have earned millions of yuan unexpectedly after a stone found in the liver of one of his sheep was judged to be a rare substance used for traditional Chinese medicine. The grey stone, about the size of a ping-pong ball and spotted with darker patches, develops from food residue in a sheep’s stomach, the Qingdao Evening News reported local animal experts as saying. The farmer, who bought the ewe from a local market several months ago intending to breed lambs from it, learned on the internet that two such stones that added up to the same weight as his could be worth several million yuan. Highly prized ‘caterpillar fungus’ declared a danger to health by China’s food and drug administration The 66-year-old from Jiaozhou noticed the animal hadn’t eaten much recently and was getting thinner, so decided to kill it and sell the meat. On the advice of neighbours, his family called the newspaper to invite local experts to determine the composition of the stone, which is about 4cm long and weighs 50 grams. An engineer from the municipal wildlife protection station said it was yangbao , or sheep’s treasure, valued in traditional Chinese medicine. It is believed to have similar medical values as cow gallstone, which according to traditional medicine is useful for treating sore throats, uraemia and even unconsciousness.