Magu Brecciated Jasper (Zhejiang, China)

Magu Brecciated Jasper – Yunmenshishan (云门寺山) near Magu village (马谷村), Xiaoshan (萧山区), Hangzhou (杭州市), Zhejiang (浙江省), China (中国)

The specific locality of Yunmenshishan (Cloud Gate Temple Mountain) in the Xiaoshan District is a well-known site for high-quality ornamental stones. This specimens is a classic example of Brecciated Jasper, or more technically, a silicified volcanic breccia. This unique rock type is a product of the intense Mesozoic volcanic activity that shaped the geology of the Zhejiang province.

The formation of these pieces tells a story of dramatic geological events. The green clasts you are focusing on represent an older generation of volcanic rock that was shattered into angular fragments by tectonic or volcanic forces. These fragments were subsequently encased and cemented together by a secondary, silica-rich fluid. The vibrant red matrix that holds these green fragments together owes its colour to a high concentration of Hematite (iron oxide) within the microcrystalline quartz (SiO2) structure.

The distinct olive and leek-green hues of the clasts are likely the result of Chlorite or Epidote minerals present during the rock's initial formation. Because these fragments have been completely "silicified"—meaning their original mineral structure was replaced by silica—they possess the extreme hardness (6.5 to 7 on the Mohs scale) and the smooth, waxy luster characteristic of high-grade Jasper.

The sharp, vivid contrast between the green fragments and the deep red "Xiaoshan Red" matrix is the hallmark of material from the area of Magu Village. This striking aesthetic makes these specimens highly desirable for both geological study and lapidary work. They serve as a tangible record of ancient volcanic history, where shattered fragments were preserved and transformed into a beautiful, solid mosaic over millions of years.

Origin: Yunmenshishan (云门寺山) near Magu village (马谷村), Xiaoshan (萧山区), Hangzhou (杭州市), Zhejiang (浙江省), China (中国)
Rock type: Brecciated Jasper, silicified volcanic breccia
Size: ~9(L) x 5(H) x 4(W) cm (see scale cube), 272 g