What is "humite"

Humite \Hum"ite\, n. [Named after Sir A. Hume.] (Min.) A mineral of a transparent vitreous brown color, found in the ejected masses of Vesuvius. It is a silicate of iron and magnesia, containing fluorine.

n. (context mineral English) An orthorhombic-dipyramidal mineral containing fluorine, hydrogen, iron, magnesium, oxygen, and silicon.

Humite is a mineral found in the volcanically ejected masses of Vesuvius. It was first described in 1813 and named for Abraham Hume (1749–1838).

The humite group is a group of nesosilicates with the general formula A(SiO)(F,OH).

When A is predominantly magnesium we have the humite subgroup:

• norbergite, Mg(SiO)(F,OH)
• chondrodite, (Mg,Fe,Ti)(SiO)(F,OH,O)
• humite, (Mg,Fe)(SiO)(F,OH)
• clinohumite, (Mg,Fe)(SiO)(F,OH)

The manganese-humite subgroup has members

• alleghanyite, (Mn)(SiO)(OH,F)
• manganhumite, (Mn,Mg)(SiO)(OH)
• sonolite, Mn(SiO)(F,OH)

and the leucophoenicite subgroup has members

• ribbeite, Mn(SiO)(OH)
• leucophoenicite, (Mn,Ca,Mg,Zn)(SiO)(OH)
• jerrygibbsite (Mn,Zn)(SiO)(OH)

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