Growth channels: to be related to fingerprints. These inclusions form when a fracture of the crystal happens in the environment of formation; the fracture receives again material for its growth and healing starts. By microscope it is possible to recognize 4 levels of healing:
- level 1: open fracture in presence of liquid in the channels;
- level 2: partially healed fracture;
- level 3: fingerprint with growth channels;
- level 4: entirely healed fracture.



