Section of polished crystals of quistolite from China. It can be appreciated in a typical andalusite crystal for this mineral.
It belongs to the orthorhombic system and is classified in the group of silicates. In nature, we find it in elongated nodules that, when breaking and polishing the surface, we can appreciate the four crystals with carbon inclusions forming the cross.
The most common uses are the collection and decoration, and the most remarkable specimens are found in China and the municipality of Boal, Asturias.