The chemical components of the fiber like tourmaline:

SiO2 TiO2 CeO K2O LiO Al2O3 B2O3
41.56% 0.26% 0.52% 0.14% 1.87% 26.30% 9.33%

MgO Na2O Fe2O3 FeO MnO P2O5
0.55% 1.20% 12.19% 5.85% 0.04% 0.22%