Humite (mineral group)
The humite group is a group of nesosilicates with the general formula An(SiO4)m(F,OH)2.
When A is predominantly magnesium we have the humite subgroup:
The manganese-humite subgroup has members
and the leucophoenicite subgroup has members
Chondrodite is the most common member of the humite group. It may contain Ti up to 9.6% TiO2. Chondrodite from Sterling Hill Mine and Franklin Mine contains zinc to 11.5% ZnO and Mn to 36% MnO, and grades to alleghanyite.
The humite minerals commonly alter to serpentine or Mg-rich chlorite and dissolve by weathering, leaving iron oxide residues.
...
Wikipedia