Humite (mineral group) explained

The humite group^[1] is a group of nesosilicates with the general formula .

When A is predominantly magnesium we have the humite subgroup:

• norbergite,
• chondrodite,
• humite,
• clinohumite,

The manganese-humite subgroup has members

• alleghanyite,
• manganhumite,
• sonolite,

and the leucophoenicite subgroup has members

• ribbeite,
• leucophoenicite,

Chondrodite is the most common member of the humite group. It may contain Ti up to 9.6% . 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]

Notes and 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