A Sino-French cave exploration team has discovered a rare cloud-like rock formation in Xiniuyan Cave in China’s southern Guangxi Zhuang autonomous region. The “cave cloud” is a natural dolomite deposit covering an area of about 300 square metres (3,229 sq ft), according Chinese state media. The July 2022 report described the cloud as only the second formation of its kind found in China. Dolomite is a soluble mineral that relatively rarely forms such structures in karst caves, according to…