Scientific Name: Limestone matrix with andalusite crystals
Group: Silicates - neosilicates
Chemical composition: Al2OSiO5
Colors: Dark grey to black with white crystals forming random patterns.
Hardness: 5 to 6
Principal Sources: California, USA
Special Notes: This is a limestone matrix with andalusite crystals. It is also called Porphory. It received the name Chinese Writing Rock or Stone because of the crystalline structure resembling the Chinese characters of the written language. It strongly resembles the Chrysanthemum stone, another limestone matrix and andalusite crystal stone from China, but the crystals in that stone spray out into a chrysanthemum pattern - hence the name.