General Information:
Chemical Formula:
(Mn++,Fe+++)3(Nb,Ta,Ti)2(Nb,Mn)2(W,Ta)2O20
Environment:
In granitic pegmatites.
IMA Status:
Approved IMA 1995
Locality:
Vez-Dara River valley, Shakhdara Range, in the southwestern Pamir Mountains, Tajikistan.
Name Origin:
Named after Aleksei Aleksandrovich Korago (1942-1993), geologist who investigated the formation of river pearls in the Arkhangel'sk district of Russia, and the origin of amber.
Physical Properties:
Cleavage:
None
Color:
red or brownish red.
Density:
4.7 - 6.22, Average = 5.46
Diaphaniety:
Opaque
Habits:
Platy - Sheet forms (e.g. micas)., ,
Hardness:
4-5 - Fluorite-Apatite
Luster:
Metallic
Streak:
grayish brown
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