Who owns the biggest emerald? HONG KONG - A giant, uncut emerald on display in Hong Kong has become the center of a dispute with Madagascar, whose government said Tuesday the stone was illegally taken from the African island nation. The 536-kg (1,179-pound) gemstone belongs to Madagascar and was extracted from one of the country's mines last July, said Luc Herve Rakotoarimanana, part of a four-member delegation that recently arrived in Hong Kong in hopes of retrieving the emerald. “We need the stone back ... It's a treasure of Madagascar,” Rakotoarimanana, head of a Madagascar government department that works with Interpol, told reporters in Hong Kong. He claimed the massive emerald was the world's largest and described it as priceless. The emerald – about 125 centimeters (49.2 inches) wide and 55 centimeters (21.7 inches) in height – has been on display in a Hong Kong art gallery since June 20. The gemstone is embedded in a rock covering and is referred to as an ´emerald on matrix,? according to the gallery's Web site. A spokeswoman for the gallery, BaoQu Tang Modern Art Gallery, contends the emerald belonged to a French company called Orgaco. She declined to elaborate. The Madagascar delegation published a statement in a number of Hong Kong newspapers Monday, claiming ownership of the emerald and arguing that whoever found the emerald cheated the government by not declaring the discovery. The delegation was also seeking help from Hong Kong authorities. Police spokesman Chau Yau-fai declined comment, saying the force would not discuss individual cases. According to the gallery, the gemstone set a record in the mining industry because it survived intact, as dynamite used during extraction often breaks the matrix into small pieces.