The humite group[1] 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.[2]

References

  1. Gaines et al (1997) Dana's New Mineralogy Eighth Edition, Wiley
  2. Phillips, W R and Griffen, D T (1981) Optical Mineralogy, pages 142 to 144
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.