Pliers bracelets found on the wreckage of Nanhai No. 1 are displayed at the Maritime Silk Road Museum on Hailing Island of Yangjiang, south China's Guangdong Province, May 12, 2020. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

Photo taken on May 12, 2020 shows the archaeological site of the wreckage of Nanhai No. 1 in Yangjiang, south China's Guangdong Province. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

Photo taken on May 12, 2020 shows the archaeological site of the wreckage of Nanhai No. 1 in Yangjiang, south China's Guangdong Province. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

A gold-plated ring found on the wreckage of Nanhai No. 1 is displayed at the Maritime Silk Road Museum on Hailing Island of Yangjiang, south China's Guangdong Province, May 12, 2020. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

Combo photo taken on May 12, 2020 shows porcelains (top) and pieces of porcelain products found on the wreckage of Nanhai No. 1 in Yangjiang, south China's Guangdong Province. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

A staff member works at the archaeological site of the wreckage of Nanhai No. 1 in Yangjiang, south China's Guangdong Province, May 12, 2020. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

Photo taken on May 12, 2020 shows pieces of porcelain products found on the wreckage of Nanhai No. 1 in Yangjiang, south China's Guangdong Province. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)

A staff member cleans coins found on the wreckage of Nanhai No. 1 in Yangjiang, south China's Guangdong Province, May 12, 2020. The excavation of the Nanhai No. 1, a shipwreck dating back to the Song Dynasty (960 A.D.-1279 A.D.), was listed by China in its top 10 archaeological discoveries for 2019. More than 180,000 relics including porcelain products, gold, silver, copper and iron relics and coins have been found from this ancient merchant ship. (Xinhua/Deng Hua)