Images
Formula: Na(NaCa)(Mg4Al)(Si7Al)O22(OH)2
Inosilicate (chain silicate), double chains,
katophorite root name group,
sodium-calcium amphibole subgroup,
w(OH,F,Cl)-dominant amphibole group,
amphibole supergroup
Crystal system: Monoclinic
Specific gravity: 3.091 calculated
Hardness: 5
Colour: Black,dark green-black, bluish black
Environments:
Igneous environments
Metamorphic environments
Katophorite was defined as the katophorite group mineral with Fe and Al as the dominant elements in the C
position up until 1997. The katophorite group was redefined in 2012, renaming the Fe2+ and Al dominant
member of the group ferro-katophorite. The name katophorite is now used for the Mg and Al dominant member of the
group, which previously was named magnesiokatophorite
(Mindat).
Katophorite occurs in alkalic volcanic and plutonic igneous rocks, and in
blueschist facies
jadeite
rock. Associated minerals include arfvedsonite,
aegirine, nepheline,
eckermannite and
chromite
(HOM).
Localities
At the type locality, the Hpakant-Tawmaw Jade Tract, Hpakant Township, Mohnyin District, Kachin State, Myanmar,
katophorite is found that is pleochroic in plane-polarised light, with X = pale blue (medium), Y = light
blue-green (strongest) and Z = colourless
(MM 79.2.355–363).
At the Kovdor Phlogopite mine, Kovdor Massif, Kovdorsky District, Murmansk Oblast, Russia, katophorite
has been found with diopside
(Mindat photo).
Katophorite from the Kovdor Phlogopite mine -
Image
At the Shields River basin, Montana, USA, katophorite is found in basic alkaline igneous rocks forming rims on
aegirine
(Webmin).
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