Humite (mineral group)
Encyclopedia
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.
When A is predominantly magnesium
Magnesium
Magnesium is a chemical element with the symbol Mg, atomic number 12, and common oxidation number +2. It is an alkaline earth metal and the eighth most abundant element in the Earth's crust and ninth in the known universe as a whole...
we have the humite subgroup:
- norbergite, Mg3(SiO4)(F,OH)2
- chondrodite, (Mg,Fe,Ti)5(SiO4)2(F,OH,O)2
- humiteHumiteHumite is a mineral found in the volcanically ejected masses of Vesuvius. It was first described in 1813 and named for Abraham Hume .-See also:* Jerrygibbsite* Chondrodite* Clinohumite* Alleghanyite...
, (Mg,Fe)7(SiO4)3(F,OH)2 - clinohumiteClinohumiteClinohumite is an uncommon member of the humite group, a magnesium silicate according to the chemical formula 942. Most commonly found as tiny indistinct grains, large euhedral clinohumite crystals are sought by collectors and occasionally fashioned into bright, yellow-orange gemstones...
, (Mg,Fe)9(SiO4)4(F,OH)2
The manganese
Manganese
Manganese is a chemical element, designated by the symbol Mn. It has the atomic number 25. It is found as a free element in nature , and in many minerals...
-humite subgroup has members
- alleghanyiteAlleghanyiteAlleghanyite is a moderately rare humite mineral with formula Mn522, belonging to the nesosilicates class. In general its occurrences are related with metamorphic manganese deposits. The mineral is named after Alleghany County, North Carolina, USA....
, (Mn2+)5(SiO4)2(OH,F)2 - manganhumite, (Mn,Mg)7(SiO4)3(OH)2
- sonolite, Mn9(SiO4)4(F,OH)2
and the leucophoenicite subgroup has members
- ribbeite, Mn5(SiO4)2(OH)2
- leucophoenicite, (Mn,Ca,Mg,Zn)(SiO4)3(OH)2
- jerrygibbsiteJerrygibbsiteJerrygibbsite is a rare silicate mineral with chemical formula: 942. Jerrygibbsite was originally discovered by Pete J. Dunn in 1984, who named it after mineralogist Gerald V. Gibbs. It has only been reported from the type locality of Franklin Furnace, New Jersey, United States, and in Namibia's...
(Mn,Zn)9(SiO4)4(OH)2
Chondrodite is the most common member of the humite group. It may contain Ti up to 9.6% TiO2. Chondrodite from Sterling Hill Mine
Sterling Hill Mining Museum
The Sterling Hill Mine, now known as the Sterling Hill Mining Museum, is a former iron and zinc mine in Ogdensburg, New Jersey. It was the last working underground mine in New Jersey when it closed in 1986. It became a museum in 1989. Along with the nearby Franklin Mine, it is known for its...
and Franklin Mine
Franklin Furnace
Franklin Furnace, also known as the Franklin Mine, is a famous mineral location for rare zinc, iron, manganese minerals in old mines in Franklin, New Jersey, USA. This locale produced more species of minerals and more different fluorescent minerals than any other location...
contains zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...
to 11.5% ZnO and Mn to 36% MnO, and grades to alleghanyite.
The humite minerals commonly alter to serpentine or Mg-rich chlorite
Chlorite group
The chlorites are a group of phyllosilicate minerals. Chlorites can be described by the following four endmembers based on their chemistry via substitution of the following four elements in the silicate lattice; Mg, Fe, Ni, and Mn....
and dissolve by weathering
Weathering
Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...
, leaving iron oxide
Iron oxide
Iron oxides are chemical compounds composed of iron and oxygen. All together, there are sixteen known iron oxides and oxyhydroxides.Iron oxides and oxide-hydroxides are widespread in nature, play an important role in many geological and biological processes, and are widely utilized by humans, e.g.,...
residues.