☐{Mg2}{Mg5}(Si8O22)(OH)2
The anthophyllite group are orthorhombic amphiboles in the magnesium-iron-manganese amphibole subgroup. The minerals in this root name group may have either Pnma or Pnmn (proto- prefixed name) space group symmetry. The anthophyllite group's composition is defined with A(Na+K+2Ca)<0.5 apfu and C(Al+Fe3++2Ti)<1 apfu.
Proto-anthophyllite is defined with Pnmm symmetry and Mg as the dominant element both in the B and C positions.
