A patient of stone and gold
In Chongqing, China, at the UNESCO World Heritage Site of Dazu Rock Carvings, a monumental statue required extensive medical attention. The patient was the Thousand-Arm Avalokitesvara (or Guanyin), a sandstone carving standing 7.7 meters tall and 12.5 meters wide. Created during the Southern Song Dynasty (1127-1279), the statue had suffered the effects of eight centuries of humidity and human interaction.
Conservators diagnosed the stone figure with 34 distinct ailments. Its surface was covered in decay: cracks spiderwebbed across the body, previous repairs were failing, and large sections of the delicate gold leaf gilding had peeled away. In 2007, one of its many fingers detached and fell. The statue covers a cliff area of 88 square meters, and the sheer scale of the damage presented an enormous challenge. This wasn't just the restoration of a relic; and a scientific intervention on a piece of a mountain. The project, designated the No. 1 national stone cultural relic protection project, began in 2008.
The high-tech conservation effort
The eight-year restoration process used modern diagnostics and traditional craftsmanship. To understand the statue's internal condition without causing further damage, scientists first used non-invasive imaging techniques. Portable X-ray radiography allowed the team to peer inside the stone, revealing the extent of internal cracks and the nature of historical repairs. They employed 3D laser scanning and close-range photogrammetry to create a precise digital model of the entire 88-square-meter surface. This digital blueprint documented every flaw and guided the physical restoration of its 830 salvageable hands.
The physical work was meticulous. Conservators consolidated the fragile sandstone structure and carefully cleaned the surfaces. They reattached hundreds of fragments and stabilized the entire sculpture. The final, most visible step was the re-gilding. Over one million pieces of gold foil were applied to the statue's surface, restoring its appearance. The entire process cost approximately 60 million yuan (US$9.8 million). The restored Avalokitesvara was revealed to the public on June 13, 2015.