Size : 15x 5.5 x 18cm. This extremely rare type of dendritic limestone was taken from a rock formation of the permian era, approximately 250 million years, at Guanxi Province. The dendritic black "tree sahpes" minerals are manganese oxide mineral that seeping and trating inti the stone along the cracks and fissures. The hardness of the stone is like 3-3,5 mohs.
The ordinary limestone it reacts strongly with hidrocholoric acid. In order to preseve its compactness add color this picture stone is protected bye a thin crystals coats. Thank you for your understanding and patience. Safer, more convenient and faster.